How to interpret the residual colors on a mosaic plot?

This is a mosaic plot of contingency table dataset HairEyeColor described here.

How do I interpret the colors representing residuals? What is the difference between high and positive Pearson's residuals (shown in blue) versus low and negative ones shown in red?

• Is there a way t change colors following the next criteria: if more than expected is for good, then cells with cases over expected should be colored in green if less than expected is for good, then cells with cases below expected should be colored in green Nov 21 '20 at 18:19