Fix #172 Volume rendering and colourmap 'colour' throws OpenGL fragment shader error
Fix #172 Volume rendering and colourmap 'colour' throws OpenGL fragment shader error

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3