NO.
Values below the first caxis value are always assigned the lowest color in the color map.
Values above the second caxis value are always assigned the highest color in the color map.
In-between, the ratio: (value - caxis(1))/(caxis(2)-caxis(1)) is calculated, and that gives you the linear portion of the way through the colormap that is used.
There is no way to say to use a particular colormap entry for a particular range of values, and a different colormap entry for a different range of values.
What you can do is create a colormap with 27 entries. Assign the same white color to the first two. Assign black to the remaining 25 entries. The span of values is 81, so the first three values (0, 1, 2) would use the "first" white slot, the second three values (3, 4, 5) would use the "second" white slot, and all other values would use some other slot that would happen to hold black.
But it is typically easier instead,
bin = discretize(x, [0 5 80 inf])
