Color method
Check contrast before the color ships
Measure the text color against the color behind it, record the ratio, and keep a failing pair out of the handoff.
A palette can look calm and still fail the person who has to read it. This guide puts one contrast check in front of a color handoff.
Measure the pair a person actually reads
Pick the text and the color directly behind that text. A page background is the wrong sample when a card, a button, or an image sits behind the words.
Write the two color values and the contrast ratio. A fictional pair is #5C6570 on #F4F1EA. Record the ratio from the tool you used and the tool name. Do not estimate the ratio by eye.
Use the size you shipped
Normal text has a higher minimum than large text. Check the size that is on the page, not the size in a brand board.
The WCAG 2.2 minimum for normal text is 4.5 to 1. Large text can meet 3 to 1. If your text is below the large-text size, do not use the lower number.
Keep a failing pair in the note
If the ratio misses the line, the handoff says so. Changing the color later does not erase the first measurement.
Recheck the same pair after the change. A new background image can drop the ratio again even when the text color stayed put.