Please describe the problem:
If you set the negative numbers representation as red numbers and perform the sum of a range with negative result there is no way to notice that the value in the status bar is negative, because the number is displayed in black (or the gtk theme font color) and without the minus symbol

Steps to reproduce:
1. choose display negative numbers in red (without minus symbol)
2. SUM a range of colums that give a negative result
3. Look to the status bar


Actual results:
It's impossible to guess if the result is negative or  not 

Expected results:
If the result is negative i would expect to notice it in an easier way (adding a minus symbol, perhaps)

Does this happen every time?
Yes

Other information: