When your app is infinitely white-labeled, every tenant picks their own colors — and every theme still has to stay legible. Contrast is the primary accessibility concern, and color drives it. So how do you guarantee contrast across thousands of color systems you've never seen?
Geometry. Color isn't a value — it's a position in space, and every color model is a different shape wrapped around human vision. This session makes that literal: no slides, just a Flutter app I drive live, where each color space is a shape you rotate and morph into the next.
We start with one idea — can you bend the axes to make a shape simpler? That move, reshaping space to ease the math, runs from Newton's wheel through modern color spaces to the perceptually uniform CIELAB and CIELUV, where distance finally means perceived difference — exactly what contrast needs. It lands on HSLuv: perceptually honest, in-gamut, and a drop-in for Flutter via the hsluv package.
You'll leave able to:

Design color systems that hold contrast at scale, across themes you don't control.
Read any color model as a coordinate transform — and see why perceptual uniformity makes contrast predictable.
Ship perceptually uniform, accessible color in Flutter with the hsluv package.