Standard Control Fill Color in VB.NET/ASP.NET

Hi,

We are working on a .NET (ASP.NET/VB.NET) application with SQL Server database. In our application, we are using some standard controls and some custom controls (like list boxes, text boxes).

For all the controls, we have some font colors and text colors fixed. But when we test from different operating systems (Windows 2000/XP etc.), the font colors and fill colors of the standard controls are changing to some other colors than what we set for the contorls while they are alright for the custom controls.

What could be the problem and what could be the solution? Help greatly appreciated

Thanks
oursmp