Recently I was asked which tools I use to check accessibility.
Of course, like so many web developers, I rely on Web Content Accessibility Guidelines (WCAG) which are maintained by the World Wide Web Consortium (W3C). The most current version of the guidelines are WCAG 2.1, with WCAG 2.2 due to be released in November this year. (WCAG 2.2 is out for public comment currently.) The World Wide Web Consortium (W3C) has a pretty comprehensive list of tools, see https://www.w3.org/WAI/test-evaluate/#tools.
Here is my short list of tools that I like and use:-
Accessible colour generator – https://learnui.design/tools/accessible-color-generator.html
Again from Webaim – https://webaim.org/resources/contrastchecker
Other useful tools
Palette generator – https://coolors.co
Palette generator – https://mycolor.space
Sass colour generator (helps with lightening, darkening and desaturating colors) – http://scg.ar-ch.org