The simplest, easiest tool for quickly finding good contrast:
As you type, the contrast ratio indicated will update. Hover over the circle to get more detailed information. When semi-transparent colors are involved as backgrounds, the contrast ratio will have an error margin, to account for the different colors they may be over.
Curated by (Lifekludger)
Read full article at Source: Contrast Ratio: Easily calculate color contrast ratios. Passing WCAG was never this easy!