Low contrast makes text hard to read, especially for people with low vision. WCAG asks for at least 4.5:1 for normal text.
Questions
What ratio do I need?
4.5:1 for body text (AA), 3:1 for large text and icons. 7:1 meets the stricter AAA level.
Contrast Checker
Check the contrast ratio between text and background colours against WCAG AA and AAA accessibility guidelines.