This checklist uses The Web Content Accessibility Guidelines (WCAG) as a reference point, which is a shared standard for web content accessibility for individuals, organizations, and governments.
WAVE Web Accessibility Evaluation Tools
WAVE is a free web accessibility evaluation tool that identifies ways to make a webpage more accessible to people with disabilities.
WhoCanUse - color checker
It's a tool that brings attention and understanding to how color contrast can affect different people with visual impairments.