get Channel Name
Get a component (channel) name from the colour space at a given index (0-2).
Return
the name of the channel, or null if the index is out of bounds
Parameters
idx
the index of the channel, 0-2
Get a component (channel) name from the colour space at a given index (0-2).
the name of the channel, or null if the index is out of bounds
the index of the channel, 0-2