I am trying to write a software to draw simple shapes under X. I use the XLib. Every went smoothly at the begining. As I need some flashing colors, I tried to create my own colormap. After creating a window with the right visaul (DirectColor), I tried to create my colormap with the same visual and I get the following error message: X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 78 (X_CreateColormap) Value in failed request: 0x0 Serial number of failed request: 9 Current serial number in output stream: 11 I have no idea how to debug this. Which value, which integer. Does the problem come from my Ubuntu? Does anyone have any idea? Is Ubuntu compliant with X standarts?