In the manual it shows:
SOUND COLOR
SOUND 1(5.6M)
SOUND 2(5.6M)
SOUND 3(11M)
SOUND 4(11M)
The AK4499EX operates at a sampling rate of 5.6448MHz.
The AK4499EX operates at a sampling rate of 11.2896MHz.
I have a DO300EX with the same selections, trying to figure out what the effect is since I can't seem to hear a difference. Ever since the M300 came out with them, even SMSL support is incredibly vague in explaining what they do exactly. Don't know anyone who's done measurements on the color settings to see if there's a difference that can be measured.