Address #95 by using f suffix on floats in color_palette.c
Change to reduce compiler warnings in color_palette.c on some compilers by specifying all floating point values that are being loaded from literals into float values with the f suffix.
MS Compilers of recent generations default to type double unless there is a f suffix, see https://msdn.microsoft.com/en-us/library/c70dax92.aspx section on floating point literals for details. This, at high warning levels, results in a lot of warnings.