How do I change matlab colorbar scaling

From your comment, I see what you are trying to do.

You are on the right lines setting ytick, but as you noticed this only changes the position of the ticks on your colorbar, but the scaling stays the same. Instead, try to set yticklabel:

% Show the colorbar
c = colorbar;

% Define the desired ticks
ticks = [0:10:180];

% Sets the correct location and number of ticks
set(c, 'ytick', ticks / max(ticks));

% Set the tick labels as desired
set(c, 'yticklabel', ticks);