change-theme

Design

Updates the shadcn/ui theme by editing OKLCH CSS custom properties in apps/core/styles/tailwind.css. Use when the user wants to change colors, theme appearance, or match a brand palette.

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Source SKILL.md: https://github.com/pagezero-dev/pagezero/blob/HEAD/.agents/skills/change-theme/SKILL.md

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Change Theme

Modify the shadcn/ui theme by updating CSS custom properties in apps/core/styles/tailwind.css.

Gather Information

Ask the user in a single question:

What theme style would you like? (e.g., "blue primary color", "warm and rounded", "minimal with sharp corners", or a specific hex color to match)

Theme File Location

The theme is defined in apps/core/styles/tailwind.css with CSS custom properties using the OKLCH color space.

Theme Structure

The file contains three main sections:

:root - Light mode colors (lines 73-106)
.dark - Dark mode colors (lines 110-142)
@theme inline - Tailwind color mappings (lines 33-69)

Available Color Variables

Variable	Purpose
`--background`	Page background
`--foreground`	Default text color
`--card`	Card backgrounds
`--card-foreground`	Card text
`--popover`	Popover/dropdown backgrounds
`--popover-foreground`	Popover text
`--primary`	Primary brand color (buttons, links)
`--primary-foreground`	Text on primary color
`--secondary`	Secondary actions
`--secondary-foreground`	Text on secondary
`--muted`	Muted backgrounds
`--muted-foreground`	Muted/subtle text
`--accent`	Accent highlights
`--accent-foreground`	Text on accent
`--destructive`	Error/danger states
`--border`	Border colors
`--input`	Input field borders
`--ring`	Focus ring color
`--radius`	Border radius base value
`--chart-1` to `--chart-5`	Chart colors
`--sidebar-*`	Sidebar-specific colors

Color Format

Colors use OKLCH format: oklch(lightness chroma hue)

Lightness: 0 (black) to 1 (white)
Chroma: 0 (gray) to ~0.4 (vivid)
Hue: 0-360 degrees (red=0, green=142, blue=264, etc.)

Instructions

When the user requests a theme change:

Identify which color variables need to change
Update values in both :root (light) and .dark sections
Ensure sufficient contrast between foreground/background pairs
Keep the OKLCH format for consistency

Tips

Use oklch.com to pick colors
Test both light and dark modes
Ensure accessibility (contrast ratios)