A simple plugin for Sketch that calculates the colour contrast of two layers and evaluates it against the Web Content Accessibility Guidelines. Colour Contrast Analyser for Sketch will give you a score of AAA, AA or fail because of a lack of contrast. And even when you do not need to meet those requirements, you can get a feeling for the contrast when you get used to the values. If only a single layer is selected, than it will calculate with its artboard background colour. Making your app accessible to more people is extremely important and this plugin should make designing it easier.