Matrix into Colour Map


I trying to convert an unsigned value NxM matrix into a colourmap (like imagesrc - in Octave) in C# SharpGL. I’m new in opengl and Learning from last 2 weeks. So many article and tutorial I have read I didn’t get a clear idea. The nxm matrix has created from Gaussian 2D Filter. If anyone knows about Heatmap creation pls share your suggestion and ideas.