Finding	
A few bugs related to expression stepping coloring showed up during the study when debugging multi-
line expression:
The green underlines indicating computed expressions were hidden when the program counter moved 
to the second line in the expression.
If there was a breakpoint on the first expression line and the program counter moved to the second line 
then the first line was displayed with breakpoint background color.

Severity	
The coloring needs to be improved.

Recommendation	
Make sure the green underlines are always visible while evaluating the same expression. It should not 
matter whether it is on multiple lines.
The breakpoint color should be shown after leaving the whole expression, not after leaving one line. In 
any case the green underlines should be always visible.