Why AI-Generated UIs Are All the Same Color — And the Data to Prove It

Why AI-Generated UIs Are All the Same Color — And the Data to Prove It Have you ever noticed that AI-generated websites all look... blue-purple? It's not your imagination. I ran 480 experiments to find out why. The Experiment I showed 40 color swatches to 4 Vision-Language Models (GPT-4o, Claude 3.5 Sonnet, Claude Sonnet 4, LLaVA 7B) and asked: "What's the HEX code of this color?" Three trials per color, per model. 480 data points total, evaluated using CIEDE2000 — the industry standard for perceptual color difference. Full paper: AI Blue: Systematic Color Recognition Bias in Vision-Language Models (DOI: 10.5281/zenodo.19159702) Code & data: github.com/kenimo49/ai-blue-color-bias Three Patterns Emerged Pattern 1: Pure colors are fine. In-between colors break. Red, blue, green, yellow — models nail these almost perfectly. But teal, lime green, chartreuse, mauve? Accuracy drops dramatically. Why? Web text is full of "red" and "blue" but rarely mentions "chartreuse." The models default to