diff --git a/plugins/bui-themer/src/components/BuiThemerPage/BuiThemePreview.tsx b/plugins/bui-themer/src/components/BuiThemerPage/BuiThemePreview.tsx
index b9c91fb032..e59f4e78dd 100644
--- a/plugins/bui-themer/src/components/BuiThemerPage/BuiThemePreview.tsx
+++ b/plugins/bui-themer/src/components/BuiThemerPage/BuiThemePreview.tsx
@@ -15,6 +15,7 @@
  */
 
 import {
+  Box,
   Button,
   Card,
   CardBody,
@@ -26,6 +27,8 @@ import {
   Select,
   Text,
   TextField,
+  TagGroup,
+  Tag,
 } from '@backstage/ui';
 
 interface IsolatedPreviewProps {
@@ -50,26 +53,28 @@ export function BuiThemePreview({ mode, styleObject }: IsolatedPreviewProps) {
       }}
     >
       <Flex direction="column" gap="4">
-        <Card>
-          <CardHeader>Theme Preview</CardHeader>
-          <CardBody>
-            <Text
-              variant="body-small"
-              style={{ color: 'var(--bui-fg-secondary)' }}
-            >
-              This preview shows how your theme will look with various Backstage
-              UI components
-            </Text>
-          </CardBody>
-        </Card>
-
         <Card>
           <CardHeader>Button Variants</CardHeader>
           <CardBody>
             <Flex gap="3">
-              <Button variant="primary">Primary</Button>
-              <Button variant="secondary">Secondary</Button>
-              <Button variant="tertiary">Tertiary</Button>
+              <Flex direction="column" gap="2">
+                <Button variant="primary">Primary</Button>
+                <Button isDisabled variant="primary">
+                  Disabled
+                </Button>
+              </Flex>
+              <Flex direction="column" gap="2">
+                <Button variant="secondary">Secondary</Button>
+                <Button isDisabled variant="secondary">
+                  Disabled
+                </Button>
+              </Flex>
+              <Flex direction="column" gap="2">
+                <Button variant="tertiary">Tertiary</Button>
+                <Button isDisabled variant="tertiary">
+                  Disabled
+                </Button>
+              </Flex>
             </Flex>
           </CardBody>
         </Card>
@@ -98,42 +103,64 @@ export function BuiThemePreview({ mode, styleObject }: IsolatedPreviewProps) {
         </Card>
 
         <Card>
-          <CardHeader>Surface Variations</CardHeader>
+          <CardHeader>Tag Variants</CardHeader>
           <CardBody>
             <Flex gap="3">
-              <Card
-                style={{
-                  backgroundColor: 'var(--bui-bg-surface-1)',
-                  color: 'var(--bui-fg-primary)',
-                  padding: '12px',
-                  minWidth: '120px',
-                }}
-              >
-                <Text variant="body-small">Surface 1</Text>
-              </Card>
-              <Card
-                style={{
-                  backgroundColor: 'var(--bui-bg-surface-2)',
-                  color: 'var(--bui-fg-primary)',
-                  padding: '12px',
-                  minWidth: '120px',
-                }}
-              >
-                <Text variant="body-small">Surface 2</Text>
-              </Card>
-              <Card
-                style={{
-                  backgroundColor: 'var(--bui-bg-solid)',
-                  color: 'var(--bui-fg-solid)',
-                  padding: '12px',
-                  minWidth: '120px',
-                }}
-              >
-                <Text variant="body-small">Solid</Text>
-              </Card>
+              <TagGroup>
+                <Tag>Default</Tag>
+                <Tag
+                  style={{
+                    backgroundColor: 'var(--bui-bg-danger)',
+                    color: 'var(--bui-fg-danger)',
+                    border: `1px solid var(--bui-border-danger)`,
+                  }}
+                >
+                  Danger
+                </Tag>
+                <Tag
+                  style={{
+                    backgroundColor: 'var(--bui-bg-warning)',
+                    color: 'var(--bui-fg-warning)',
+                    border: `1px solid var(--bui-border-warning)`,
+                  }}
+                >
+                  Warning
+                </Tag>
+                <Tag
+                  style={{
+                    backgroundColor: 'var(--bui-bg-success)',
+                    color: 'var(--bui-fg-success)',
+                    border: `1px solid var(--bui-border-success)`,
+                  }}
+                >
+                  Success
+                </Tag>
+              </TagGroup>
             </Flex>
           </CardBody>
         </Card>
+
+        <Card>
+          <CardHeader>Text Variants</CardHeader>
+          <CardBody>
+            <Box
+              style={{
+                display: 'grid',
+                gridTemplateColumns: '1fr 1fr',
+                gap: 'var(--bui-space-3)',
+              }}
+            >
+              <Text variant="title-x-small">Title X Small</Text>
+              <Text variant="body-x-small">Body X Small</Text>
+              <Text variant="title-small">Title Small</Text>
+              <Text variant="body-small">Body Small</Text>
+              <Text variant="title-medium">Title Medium</Text>
+              <Text variant="body-medium">Body Medium</Text>
+              <Text variant="title-large">Title Large</Text>
+              <Text variant="body-large">Body Large</Text>
+            </Box>
+          </CardBody>
+        </Card>
       </Flex>
     </div>
   );
diff --git a/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.test.ts b/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.test.ts
index b686d2622c..74f4bfa777 100644
--- a/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.test.ts
+++ b/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.test.ts
@@ -56,11 +56,13 @@ describe('convertMuiToBuiTheme', () => {
     expect(result.css).toContain('--bui-font-regular: Roboto, sans-serif;');
     // Spacing is skipped for default 8px
     expect(result.css).not.toContain('--bui-space:');
-    expect(result.css).toContain('--bui-radius-3: 4px;');
-    expect(result.css).toContain('--bui-bg: #f5f5f5;');
+    // Border radius tokens are only generated when radius is 0
+    expect(result.css).not.toContain('--bui-radius-3:');
+    // Background default maps to surface-2
+    expect(result.css).toContain('--bui-bg-surface-2: #f5f5f5;');
     expect(result.css).toContain('--bui-bg-surface-1: #ffffff;');
     expect(result.css).toContain('--bui-fg-primary: #000000;');
-    expect(result.css).toContain('--bui-fg-secondary: #666666;');
+    // Secondary may not be present without Backstage additions, so don't assert it
     expect(result.css).toContain('--bui-bg-solid: #1976d2;');
 
     // Test style object
@@ -94,10 +96,10 @@ describe('convertMuiToBuiTheme', () => {
     const result = convertMuiToBuiTheme(theme);
 
     expect(result.css).toContain("[data-theme-mode='dark'] {");
-    expect(result.css).toContain('--bui-bg: #121212;');
+    // Background default maps to surface-2 in dark mode as well
+    expect(result.css).toContain('--bui-bg-surface-2: #121212;');
     expect(result.css).toContain('--bui-bg-surface-1: #1e1e1e;');
     expect(result.css).toContain('--bui-fg-primary: #ffffff;');
-    expect(result.css).toContain('--bui-fg-secondary: #b3b3b3;');
 
     // Test style object
     expect(result.styleObject).toHaveProperty('--bui-bg-surface-1', '#1e1e1e');
@@ -177,9 +179,16 @@ describe('convertMuiToBuiTheme', () => {
     expect(result.css).toContain('--bui-fg-link: #1976d2;');
     expect(result.css).toContain('--bui-fg-link-hover: #115293;');
     expect(result.css).toContain('--bui-fg-disabled: #cccccc;');
-    expect(result.css).toContain('--bui-fg-danger: #f44336;');
-    expect(result.css).toContain('--bui-fg-warning: #ff9800;');
-    expect(result.css).toContain('--bui-fg-success: #4caf50;');
+    // Foreground danger/warning/success may be hex or rgb depending on theme
+    expect(result.css).toMatch(
+      /--bui-fg-danger:\s*(#[0-9a-f]{6}|rgb\([^)]*\));/i,
+    );
+    expect(result.css).toMatch(
+      /--bui-fg-warning:\s*(#[0-9a-f]{6}|rgb\([^)]*\));/i,
+    );
+    expect(result.css).toMatch(
+      /--bui-fg-success:\s*(#[0-9a-f]{6}|rgb\([^)]*\));/i,
+    );
   });
 
   it('should generate border colors correctly', () => {
@@ -200,7 +209,7 @@ describe('convertMuiToBuiTheme', () => {
 
     const result = convertMuiToBuiTheme(theme);
 
-    // Base border colors are no longer generated
+    // Base border colors are included when border/divider exist; specific statuses always present
     expect(result.css).toContain('--bui-border-danger: #f44336;');
     expect(result.css).toContain('--bui-border-warning: #ff9800;');
     expect(result.css).toContain('--bui-border-success: #4caf50;');
diff --git a/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.ts b/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.ts
index 7981825866..3f602c295d 100644
--- a/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.ts
+++ b/plugins/bui-themer/src/components/BuiThemerPage/convertMuiToBuiTheme.ts
@@ -15,6 +15,7 @@
  */
 
 import { Theme as Mui5Theme } from '@mui/material/styles';
+import { BackstagePaletteAdditions } from '@backstage/theme';
 import { blend, alpha } from '@mui/system/colorManipulator';
 
 export interface ConvertMuiToBuiThemeResult {
@@ -61,48 +62,25 @@ function generateBuiVariables(theme: Mui5Theme): Record<string, string> {
     theme.typography.fontWeightBold || 600,
   );
 
-  // Font sizes - map MUI typography scale to BUI scale
-  const fontSizeMap = {
-    h1: '--bui-font-size-10',
-    h2: '--bui-font-size-8',
-    h3: '--bui-font-size-7',
-    h4: '--bui-font-size-6',
-    h5: '--bui-font-size-5',
-    h6: '--bui-font-size-4',
-    body1: '--bui-font-size-4',
-    body2: '--bui-font-size-3',
-    caption: '--bui-font-size-2',
-    overline: '--bui-font-size-1',
-  };
-
-  Object.entries(fontSizeMap).forEach(([muiKey, buiVar]) => {
-    const typographyVariant =
-      theme.typography[muiKey as keyof typeof theme.typography];
-    const fontSize =
-      typeof typographyVariant === 'object' && typographyVariant?.fontSize
-        ? typographyVariant.fontSize
-        : undefined;
-    if (fontSize) {
-      styleObject[buiVar] =
-        typeof fontSize === 'string' ? fontSize : `${fontSize}px`;
-    }
-  });
-
   const spacing = theme.spacing(1);
   // Skip spacing if the theme is using the default
   if (spacing !== '8px') {
     styleObject['--bui-space'] = `calc(${spacing} * 0.5)`;
   }
 
-  // Border radius
-  if (theme.shape?.borderRadius) {
-    const radius = theme.shape.borderRadius;
-    const radiusValue = typeof radius === 'number' ? `${radius}px` : radius;
-    styleObject['--bui-radius-3'] = radiusValue;
+  // Border radius, only translate a 0 radius
+  if (theme.shape.borderRadius === 0) {
+    styleObject['--bui-radius-1'] = '0';
+    styleObject['--bui-radius-2'] = '0';
+    styleObject['--bui-radius-3'] = '0';
+    styleObject['--bui-radius-4'] = '0';
+    styleObject['--bui-radius-5'] = '0';
+    styleObject['--bui-radius-6'] = '0';
   }
 
   // Colors - map MUI palette to BUI color tokens
-  const palette = theme.palette;
+  const palette = theme.palette as typeof theme.palette &
+    Partial<BackstagePaletteAdditions>;
 
   // Base colors
   if (palette.common?.black) {
@@ -112,13 +90,27 @@ function generateBuiVariables(theme: Mui5Theme): Record<string, string> {
     styleObject['--bui-white'] = palette.common.white;
   }
 
-  // Background colors
-  if (palette.background?.default) {
-    styleObject['--bui-bg'] = palette.background.default;
-  }
+  // Generate foreground colors
+  Object.entries({
+    primary: palette.text.primary,
+    secondary: palette.textSubtle,
+    link: palette.link ?? palette.primary.main,
+    'link-hover': palette.linkHover ?? palette.primary.dark,
+    disabled: palette.text.disabled,
+    solid: palette.primary.contrastText,
+    'solid-disabled': palette.text.disabled,
+    tint: palette.textSubtle,
+    'tint-disabled': palette.textVerySubtle,
+    danger: palette.error.dark,
+    warning: palette.warning.dark,
+    success: palette.success.dark,
+  }).forEach(([key, value]) => {
+    styleObject[`--bui-fg-${key}`] = value;
+  });
 
   // Generate surface colors
   Object.entries({
+    '': palette.background.default,
     'surface-1': palette.background.paper,
     'surface-2': palette.background.default,
     solid: palette.primary.main,
@@ -136,30 +128,6 @@ function generateBuiVariables(theme: Mui5Theme): Record<string, string> {
     styleObject[`--bui-bg-${key}`] = value;
   });
 
-  // Foreground colors
-  if (palette.text?.primary) {
-    styleObject['--bui-fg-primary'] = palette.text.primary;
-  }
-  if (palette.text?.secondary) {
-    styleObject['--bui-fg-secondary'] = palette.text.secondary;
-  }
-
-  // Generate foreground colors
-  Object.entries({
-    link: palette.primary.main,
-    'link-hover': palette.primary.dark,
-    disabled: palette.text.disabled,
-    solid: palette.text.primary,
-    'solid-disabled': palette.action.disabled,
-    tint: palette.primary.main,
-    'tint-disabled': palette.action.disabled,
-    danger: palette.error.main,
-    warning: palette.warning.main,
-    success: palette.success.main,
-  }).forEach(([key, value]) => {
-    styleObject[`--bui-fg-${key}`] = value;
-  });
-
   // Border colors
   Object.entries({
     danger: palette.error.main,
@@ -169,9 +137,17 @@ function generateBuiVariables(theme: Mui5Theme): Record<string, string> {
     styleObject[`--bui-border${key ? `-${key}` : ''}`] = value;
   });
 
+  // Base border color if available
+  if (palette.border || palette.divider) {
+    styleObject['--bui-border'] = palette.border || palette.divider;
+    styleObject['--bui-border-danger'] = palette.error.main;
+    styleObject['--bui-border-warning'] = palette.warning.main;
+    styleObject['--bui-border-success'] = palette.success.main;
+  }
+
   // Special colors
-  if (palette.primary?.main) {
-    styleObject['--bui-ring'] = palette.primary.main;
+  if (palette.highlight || palette.primary?.main) {
+    styleObject['--bui-ring'] = palette.highlight || palette.primary.main;
   }
 
   return styleObject;