Excel - Cell colors and windows high contrast theme

I use my Windows 7 with a high contrast theme, which is great apart from some minor problems. One such problem is Excel (2010) that won't display fore- and background colors anymore. First change Windows'high contrast mode with the key combination L-SHIFT + L-ALT + PRT SCR. This doesn't have an immediate effect (at least for me). Then, in Excel, go to File > Options > General > User Interface options, select a Color scheme and click OK. Doing so will change Excels'interface and allow fore- and background colors once more.