On the left you can see the original texture, the other two are the result of YCoCg/DXT5 compression.
The middle one is with the simplification used in the
"Real-Time DXT Compression" paper I talked about, the right one is without it.
Here you can see that there's an orange border around
all the yellow edges. In the middle one there are also some
bright green blocks.
Everything is blocky after compression, has a
washed out red appearance, and in the middle
there are some purple smudges here and there.
In the middle image there's a red glow around the top of
the yellow stripes, while the black stripes have a redish glow.
The right one isn't that much better, but the glow is more yellow,
which makes more sense since there's no red in the original.
When you look at the yellow stripes from some distance,
the middle one looks green, unlike the left and right
one which remain yellow.
I'm pretty sure these artifacts would be far less visible on higher resolution textures, but here all these artifacts are rather visible.
Update: Updated images with higher resolution versions.