What WCAG color contrast guidelines apply to sub brand logos?
Per WCAG 1.4.3 "Text that is part of a logo or brand name has no contrast requirement" so in the instance that these sub brand logo are graphics that have text in them then they will pass. If sub-brands are typed and it is not a graphical logo then these sub brands would be subject to text contrast guidelines.
However, with all of this said, if you are using graphical logos and not text and also have the flexibility with the logo design, making it able to pass contrast guidelines would be a great thing to do!
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