文本颜色与背景色 怎样的对比度才是合适的呢？

luminance 流明

Contrast 对比度

Low contrast between the foreground and background colors can make text difficult to read.

The Web Content Accessibility Guidelines (WCAG) recommend at least a 4.5 to 1 contrast ratio for normal text.

WCAG 推荐 4.5:1

使用足够的对比度来降低色盲的影响

常见的是绿色色盲，分不清两个相近的绿色，要避免这种用色

https://www.freecodecamp.org/learn/responsive-web-design/applied-accessibility/improve-readability-with-high-contrast-text