Exercise- control the strength of colour

In this exercise I have taken 5 shots of the same red 'T shirt'. With the camera in completely manual mode I have started from a setting of 1/2 stop under exposed and then increased the aperture one stop for each of the following shots. The shutter speed has been kept at 1/125 second.

f18

f16

f14

f13

f11

The under exposed shot seems to have a richer deeper colour apart from just being darker, as the exposure increases the colour gets more 'washed out' looking or less rich. I really like the richness in the under exposed frame and the strong colour. This exercise shows how the intensity of colour varies with exposure not just the brightness varying.