Fix colors for a11y

Use the new color spec. Use textColor_Inverse for textColor_onAccent, as
they are the same in QS.

Also, fix a bug where we were calling the wrong method to obtain color
for secondary label.

Fixes: 187918647
Fixes: 187489493
Test: manual
Change-Id: I2f2b62deacfa81e37854a0f9a534eca1713da1ae