not really a bug…
when morphing color from a spread with higher spreadcount to one with a lower, no of indices switch to the lower count on morph start. input morph (value) always keeps the higher no. of indices (therefore switches on morph start only to higher no.).
i would suggest for both nodes to have settings for this, i.e. delete double values after morph (currently i’m patching stuff around input morph (value) to delete those slices, e.g. when morphing from 180 values to 4, i’d get 176 repeated values without this - not working with input morph (color)).