Change colors based on certain factors

Conditional formatting can (just now) be applied to cell backgrounds in tables only - you can't use conditional formatting on cell text in tables, or on a matrix.

Shawn,

Your example looks like a matrix with Items and Quarters as columns, not measures.  You can use conditional formatting  of text in an R visual using geom_text() - see https://community.powerbi.com/t5/R-Script-Showcase/Heatmaps/td-p/68573 for a related example.