Tag
contrast
- Jan 2, 2026 Which Boundary Counts for Non-Text Contrast and Focus Indicators How the 3:1 requirement applies to component edges, icons, and focus rings, why the measured pair is the two colors on either side of a boundary, and how state changes are evaluated separately. accessibility
- Oct 2, 2024 Measuring Contrast From Rendered Pixels Why the contrast ratio is simple arithmetic but the colour inputs are not, how effective backgrounds are composited, and what sampling rendered pixels can and cannot settle. accessibility
- Sep 15, 2024 Perceptual Contrast Models and Why Weight and Polarity Change the Verdict WCAG 2 contrast is a ratio between two colors; newer models predict lightness difference from a background and scale it by text size and weight, which makes polarity and stroke thickness part of the result. accessibility
- Aug 23, 2024 Checking Contrast Against What Renders, Not What Is Declared Computed styles, compositing, canvas readback, and the sampling decisions that decide whether a measured ratio corresponds to anything a reader sees. accessibility
- Mar 7, 2024 Measuring Contrast When Text Sits on a Photograph A single foreground color over an image has a contrast ratio for every backdrop pixel; how to find the worst case, and what scrims, blur, and backdrop filters do to that distribution. accessibility
- Jan 15, 2024 Redundant Encoding: When Color Cannot Be the Only Signal Why hue collapses under monochrome rendering and common color vision deficiencies, and the concrete channels — shape, position, texture, text — that carry the same information in parallel. accessibility
- Oct 17, 2023 Computing Relative Luminance and Contrast Ratios from sRGB Values The linearisation step, the weighted sum behind relative luminance, and why the WCAG ratio adds a constant to both values before dividing them. accessibility