Yes, visually - looking at the red square, but also looking at other colors with a subtantial red component, e.g. the pink and orange squares, which shift to lavender and yellow as the red is subtracted out. The green channel also desaturates, to a lesser degree. The blue channel seems relatively resistant to the effect. This may be a result of the demosaicing algorithms that Canon uses - DxOMark shows an example of color responsiveness of the Canon 500D vs. the Nikon D5000, where you can see that the Canon's spectral response curves have substantial overlap between the red and green channels, meaning the RAW processing do a fair bit of work to unmix the colors (which makes me wonder if it really is mainly an effect in the red channel, since that would also impact the green channel based on the overlap).