[SDK] The text only buttons need to have a contrast of 4.5:1 again the background

[lwnoble]

Problem/Concern

Without sufficient contrast to see the shape of the button and without another signifier, there's nothing to signify the text is interactive. It just looks like text. Therefore, while users can still locate the text, they can't identify it as a button.

The contrast would have to be 4.5:1 unless the text size is "large", defined as 14pt bold or 18pt normal (w3.org/TR/WCAG21/#dfn-large-scale), in which case the contrast can be 3:1.

Proposed Solution

[evangk6]

Lise to investigate this issue further, before handing off