Show HN: ColoringMagician – Generate custom coloring pages using AI

Hey HN!

I made ColoringMagician because I got frustrated trying to find specific coloring pages for my niece. She's a true painter, always complaining about how she'd draw it differently if it wasn't a very generic coloring page.

It's built using a custom model, with some tweaks to generate clean line art (turns out, making AI create consistently good coloring pages is trickier than I thought!). The most interesting part was figuring out how to convert complex images into something that's actually colorable.

Things I learnt along the way:

- Kids are brutally honest beta testers - Making prompt templates is trial and error - Gemini 2.0 Flash is amazing