diff --git a/packages/preset-mini/src/rules/border.ts b/packages/preset-mini/src/rules/border.ts
index 1cdf74399f..afad7bbaa8 100644
--- a/packages/preset-mini/src/rules/border.ts
+++ b/packages/preset-mini/src/rules/border.ts
@@ -1,6 +1,6 @@
 import type { CSSEntries, CSSObject, Rule, RuleContext } from '@unocss/core'
 import type { Theme } from '../theme'
-import { colorToString, cornerMap, directionMap, globalKeywords, handler as h, hasParseableColor, parseColor } from '../utils'
+import { colorOpacityToString, colorToString, cornerMap, directionMap, globalKeywords, handler as h, hasParseableColor, parseColor } from '../utils'
 
 const borderStyles = ['solid', 'dashed', 'dotted', 'double', 'hidden', 'none', 'groove', 'ridge', 'inset', 'outset', ...globalKeywords]
 
@@ -64,14 +64,14 @@ const borderColorResolver = (direction: string) => ([, body]: string[], theme: T
     }
     if (direction === '') {
       return {
-        '--un-border-opacity': cssColor.alpha ?? 1,
-        [`border${direction}-color`]: colorToString(cssColor, `var(--un-border${direction}-opacity)`),
+        '--un-border-opacity': colorOpacityToString(cssColor),
+        'border-color': colorToString(cssColor, 'var(--un-border-opacity)'),
       }
     }
     else {
       return {
         // Separate this return since if `direction` is an empty string, the first key will be overwritten by the second.
-        '--un-border-opacity': cssColor.alpha ?? 1,
+        '--un-border-opacity': colorOpacityToString(cssColor),
         [`--un-border${direction}-opacity`]: 'var(--un-border-opacity)',
         [`border${direction}-color`]: colorToString(cssColor, `var(--un-border${direction}-opacity)`),
       }
@@ -79,7 +79,7 @@ const borderColorResolver = (direction: string) => ([, body]: string[], theme: T
   }
   else if (color) {
     return {
-      [`border${direction}-color`]: color.replace('%alpha', `${alpha ?? 1}`),
+      [`border${direction}-color`]: colorToString(color, alpha),
     }
   }
 }
diff --git a/packages/preset-mini/src/utils/colors.ts b/packages/preset-mini/src/utils/colors.ts
index 3335bbdf48..b63d624b37 100644
--- a/packages/preset-mini/src/utils/colors.ts
+++ b/packages/preset-mini/src/utils/colors.ts
@@ -34,7 +34,15 @@ export function parseCssColor(str = ''): CSSColorValue | undefined {
   return { type, components, alpha }
 }
 
-export function colorToString(color: CSSColorValue, alphaOverride?: string | number) {
+export function colorOpacityToString(color: CSSColorValue) {
+  const alpha = color.alpha ?? 1
+  return alpha === '%alpha' ? 1 : alpha
+}
+
+export function colorToString(color: CSSColorValue | string, alphaOverride?: string | number) {
+  if (typeof color === 'string')
+    return color.replace('%alpha', `${alphaOverride ?? 1}`)
+
   const { components } = color
   let { alpha, type } = color
   alpha = alphaOverride ?? alpha
diff --git a/packages/preset-mini/src/utils/utilities.ts b/packages/preset-mini/src/utils/utilities.ts
index e54235d50d..1ce4ce6907 100644
--- a/packages/preset-mini/src/utils/utilities.ts
+++ b/packages/preset-mini/src/utils/utilities.ts
@@ -1,7 +1,7 @@
 import type { CSSEntries, CSSObject, ParsedColorValue, RuleContext, VariantContext } from '@unocss/core'
 import { toArray } from '@unocss/core'
 import type { Theme } from '../theme'
-import { colorToString, getComponents, parseCssColor } from './colors'
+import { colorOpacityToString, colorToString, getComponents, parseCssColor } from './colors'
 import { handler as h } from './handlers'
 import { directionMap } from './mappings'
 
@@ -147,14 +147,14 @@ export const colorResolver = (property: string, varName: string) => ([, body]: s
     }
     else {
       return {
-        [`--un-${varName}-opacity`]: cssColor.alpha ?? 1,
+        [`--un-${varName}-opacity`]: colorOpacityToString(cssColor),
         [property]: colorToString(cssColor, `var(--un-${varName}-opacity)`),
       }
     }
   }
   else if (color) {
     return {
-      [property]: color.replace('%alpha', `${alpha ?? 1}`),
+      [property]: colorToString(color, alpha),
     }
   }
 }
diff --git a/packages/preset-wind/src/rules/background.ts b/packages/preset-wind/src/rules/background.ts
index 139ac56310..4aaaca6e98 100644
--- a/packages/preset-wind/src/rules/background.ts
+++ b/packages/preset-wind/src/rules/background.ts
@@ -1,5 +1,5 @@
 import type { Rule, RuleContext } from '@unocss/core'
-import { colorToString, handler as h, parseColor, positionMap } from '@unocss/preset-mini/utils'
+import { colorOpacityToString, colorToString, handler as h, parseColor, positionMap } from '@unocss/preset-mini/utils'
 import type { Theme } from '@unocss/preset-mini'
 
 const bgGradientColorResolver = (mode: 'from' | 'to' | 'via') =>
@@ -19,7 +19,7 @@ const bgGradientColorResolver = (mode: 'from' | 'to' | 'via') =>
       if (alpha != null)
         colorString = colorToString(cssColor, alpha)
       else
-        colorString = colorToString(cssColor, `var(--un-${mode}-opacity, ${cssColor.alpha ?? 1})`)
+        colorString = colorToString(cssColor, `var(--un-${mode}-opacity, ${colorOpacityToString(cssColor)})`)
     }
 
     switch (mode) {
diff --git a/test/__snapshots__/preset-uno.test.ts.snap b/test/__snapshots__/preset-uno.test.ts.snap
index 63966485b7..a701457204 100644
--- a/test/__snapshots__/preset-uno.test.ts.snap
+++ b/test/__snapshots__/preset-uno.test.ts.snap
@@ -6,6 +6,15 @@ exports[`targets 1`] = `
 .border-custom-b\\\\/0{border-color:rgba(var(--custom), 0);}
 .border-custom-b\\\\/10{border-color:rgba(var(--custom), 0.1);}
 .bg-custom-b{background-color:rgba(var(--custom), 1);}
+.bg-custom-c{--un-bg-opacity:1;background-color:rgba(var(--custom-c),var(--un-bg-opacity));}
+.bg-custom-c\\\\/10{background-color:rgba(var(--custom-c),0.1);}
+.bg-custom-d{background-color:hsl(var(--custom-d), 1);}
+.bg-custom-d\\\\/20{background-color:hsl(var(--custom-d), 0.2);}
+.bg-custom-e{--un-bg-opacity:1;background-color:hsla(var(--custom-e),var(--un-bg-opacity));}
+.bg-custom-e\\\\/30{background-color:hsla(var(--custom-e),0.3);}
+.bg-custom-f{--un-bg-opacity:1;background-color:lch(var(--custom-f) / var(--un-bg-opacity));}
+.bg-custom-f\\\\/\\\\[var\\\\(--f-op\\\\)\\\\]{background-color:lch(var(--custom-f) / var(--f-op));}
+.bg-custom-f\\\\/30{background-color:lch(var(--custom-f) / 0.3);}
 .bg-info{--un-bg-opacity:1;background-color:hsla(200.1,100%,54.3%,var(--un-bg-opacity));}
 .bg-info\\\\/\\\\[10\\\\%\\\\]{background-color:hsla(200.1,100%,54.3%,10%);}
 .bg-info\\\\/10{background-color:hsla(200.1,100%,54.3%,0.1);}
diff --git a/test/preset-uno.test.ts b/test/preset-uno.test.ts
index 65f16743b8..3acdf5a637 100644
--- a/test/preset-uno.test.ts
+++ b/test/preset-uno.test.ts
@@ -18,6 +18,15 @@ const targets = [
   'border-custom-b',
   'border-custom-b/0',
   'border-custom-b/10',
+  'bg-custom-c',
+  'bg-custom-c/10',
+  'bg-custom-d',
+  'bg-custom-d/20',
+  'bg-custom-e',
+  'bg-custom-e/30',
+  'bg-custom-f',
+  'bg-custom-f/30',
+  'bg-custom-f/[var(--f-op)]',
 
   // wind - placeholder
   'placeholder-red-400',
@@ -119,6 +128,10 @@ const uno = createGenerator({
       custom: {
         a: 'var(--custom)',
         b: 'rgba(var(--custom), %alpha)',
+        c: 'rgba(var(--custom-c) / %alpha)',
+        d: 'hsl(var(--custom-d), %alpha)',
+        e: 'hsl(var(--custom-e) / %alpha)',
+        f: 'lch(var(--custom-f) / %alpha)',
       },
       info: 'hsl(200.1, 100%, 54.3%)',
     },