Fading rgb color after converting to cie lab space?

I have a program which fades between rgb colors, but since RGB colors are linearly interpolated it does not look like they are making even steps so i made a function that can converted the RGB input to CIE lab space. Also now i added the function that you do cie lab space calculation for get, set and update. But i cannot get it working. The source code is here:

https://docs.google.com/file/d/0B72DnOP2_oMRWnlfVmROZEkzYW8/edit

https://docs.google.com/file/d/0B72DnOP2_oMRZzJHdFpVcldoZXM/edit

https://docs.google.com/file/d/0B72DnOP2_oMRbmxoTXBwRHdISm8/edit

So my question is when i call my dofade() function I wanted to get the rgb input, convert it into lab space and then do all the calculation in lab space and then finally convert the value into RGB and display. Please help