任何一名设计师都明白这点，文字和背景有足够的对比可以让文字更容易阅读。

Any designer knows that enough contrast between the text and background makes for easy reading of text and material.

youdao

我特意没有去设置文字和页面背景颜色。

I have specifically not set any text or page background colors.

youdao

它还增加了一个直角线，而不是一种扭曲的背景和早期CAPTCHAS做的那样对文字的高水平包装，因为后者被破解了。

It also adds an angled line, rather than a distorted background and high levels of warping on the text as earlier CAPTCHAs did, because the latter were broken.

youdao