Per the attached image,
I have a few ButtonGroups in a toolbar.
Some have button , which, when I changed themes to Default, look great, the labels stay dark.
But when I switch to Slate Theme, the labels stay dark, but the buttons light up and are more visible..

My goal is too somehow set the label StyleSpec to a style class that the buttons use, because they work.

I've tried to FireFox and locate the style: x-btn-text...
But when I try to apply to "Cls="x-btn-text" on the label , it doesn't work.

Any ideas?