From developer art to good looking apps - an AI design skill for .NET MAUI | Community Feed

Great at implementing designs but not at creating them, Mark Allibone tackles the root problem for MAUI UI July: he writes down his design opinions once as an Agent Skill so his AI assistant applies them every time, lifting apps from “developer art” to something demo-worthy.

What you’ll learn

What an Agent Skill is — a SKILL.md file the agent loads on demand, working across Claude Code, VS Code Copilot, the Copilot CLI, and the Copilot coding agent
Colour theory as rules — the 60-30-10 rule, choosing harmonies from the colour wheel, avoiding pure black/white, and treating dark mode as more than an inversion
Non-negotiable contrast — computing WCAG AA ratios and adjusting lightness until text passes
Generated resources — producing Colors.xaml and Styles.xaml with AppThemeBinding and no literal hex values
Icon fonts done right — setting up FluentUI System Icons and never letting the model guess glyph code points
Pinning a cheap model — why model: haiku runs the skill fast and cheaply since the thinking is already written down

Read the full post to see the workout-app sample (built with MAUI Reactor) and grab the complete skill on GitHub.