I'm bit surprised, that plain Crisp theme has better rating than ARIA theme when it comes to color contrast.

For example,
- white text on orange tab headers - contrast is at 2.41
- white text on purple background - 4.73

The requirement for AA is 4.5:1
and AAA is 7:1

I would expect that high contrast ARIA theme easily meets AAA requirements!
I know I can fix that in Themer, but why would anyone design "high contrast" theme that has less contrast than regular Crisp theme? There are different requirements for large and small text, but 2.41:1 is below any standard, even AA for large text!

And Sencha claims it was designed with "accessibility experts"?
What re your thought on this?

Quick reference for ARIA theme