Every colour the colour room can put on your site clears the contrast ratios WCAG 2.2 AA asks for: 4.5:1 for links and body text, 3:1 for the marks that show which page you are on. That holds right across the room — every hue, at every strength.
It is checked before a design ships rather than scanned afterwards. A design states what each of its colours has to clear, and our build re-derives every colour the room can produce and measures it. A change that falls short anywhere in that range does not ship.
This covers the colours the room offers: grounds, accents, and the text set on them. It says nothing about your own photographs or the words you write. Colour is the part of your site we can check exhaustively before you ever pick it, and we claim it only for that part.
If something on an Obio site is hard for you to use, write to hello@obio.app and we will look at it.