Test coverage percentage
WCAG 1.4.1 Use of Color requirements state:
1.4.1 Use of Color: Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. (Level A)
Our project badges use different colors to communicate information. In most cases that's perfectly fine, as the color is just there to support and as additional cue.
However, there is one case where this might be a bit more problematic. For the test coverage badge, it looks like the percentage determines the color, but there is no hint given anywhere at which percentage the color changes.
Additionally, red is being associated with something failing and aspects that require immediate attention from the user, which does not have to be the case with a low test coverage. Code with test coverage below 10% might work better than code with test coverage above 90%.