Coloring of table on input matrix table incorrect if rows of covariates come before the row of labels.

[jmelott]

See image below.

To reproduce:
Load attached matrix into GUI Builder.
matrix_with_column_covariates_labels_after_covariates.txt
Click on Row Labels option box.
Select third row of matrix in table (containing labels).
Select Column covariates option box.
Select 1st and 2nd rows of matrix in table (containing covariates)

The first cells of each covariate should be colored yellow like the rest of the rows rather than being white.
Covariate select works as expected, it's just a cosmetic issue on the displayed table.