kontrastprüfer - SERP Analysis

https://webaim.org/resources/contrastchecker/

https://coolors.co/contrast-checker

https://contrastchecker.com/

https://colourcontrast.cc/

https://imagecolorpicker.com/color-contrast-checker

https://color.adobe.com/rast-Checker-2-color-theme-19812400/

https://contrast.tools/

https://color.adobe.com/en/create/color-contrast-analyzer

https://dev.to/drewtownchi/firefox-68-0-gets-a-color-contrast-accessibility-checker-4dlg

https://www.siteimprove.com/de/toolkit/color-contrast-checker/