Try:
original = get(c, 'Position')
set(c, 'Position', [original(1) original(2)*0.5, original(3), original(4)*0.5])
c 'Position', , . , . , colorbar, :
set(get(c, 'YLabel'), 'String', {'a', 'b', 'c'}) % Arbitrary Labels
set(get(c, 'Title'), 'String', {'Colorbar Title'}); % Arbitrary Title
set(c, 'Position', [original]) % Resize back to original and observe!