The up tick and down tick colors in each viewer grid may be individually customized according to a specific column and viewer.
To change the up/down tick color of a single column, right-click on the column heading, and select "Column Settings". Click "Foreground Color..." to change the text color.
The background color of a specific column and viewer may also be changed here by unchecking the "Transparent' selection box, then left-clicking on "Background Color..."