I need to be able to make a color map for several possible categories where not all the categories show up all the time, e.g.

sample_colormap = [[0.0, ‘black’],[0.2,‘black’],[0.2,‘yellow’],[0.4,‘yellow’],[0.4,‘green’],[0.6,‘green’],[0.6,‘red’],[0.8,‘red’],[0.8,‘blue’],[1,‘blue’]]

but I have noticed that if 0 is not in the dataset then all the other colors MOVE to compensate for that (i.e. if the smallest number is 0.2 suddenly 0.2’s are rendering BLACK rather than YELLOW). How do I turn this behavior OFF? I would also note that I have attempted putting x=np.nan y=np.nan color=0 into my dataset to discourage this behavior but that does not work.

Thanks!