Koen,
Please download the latest build first.
Open the CuteSoft_Client\CuteEditor\Scripts\Constant.js file and modify the following code:
// Default Dropdown background color
editorconstant.DropDownBGColor="white";
Keep me posted
asp.net Chat http://cutesoft.net/ASP.NET+Chat/default.aspx
Web Messenger: http://cutesoft.net/Web-Messenger/default.aspx
asp.net wysiwyg editor: http://cutesoft.net/ASP.NET+WYSIWYG+Editor/default.aspx
asp wysiwyg html editor: http://cutesoft.net/ASP
asp.net Image Gallery: http://cutesoft.net/ASP.NET+Image+Gallery/default.aspx
Live Support: http://cutesoft.net/live-support/default.aspx