I have all 3, but on significantly different blades .. The Blue, Yellow, Red is the colour of the Sponge, for each variant .. In terms of Sponge hardness, I know for sure that the Blue is the softest @ 38° - 40°, the Red is the hardest @ 45° - 47°, and the Yellow sits in-between @ 40° - 42° .. Apart from the Hardness, I'm not sure whether the Sponge differs in any other aspect.
I'm pretty sure that the Topsheet of the Yellow variant is quite different from the Blue & Red ... To me, it looks (seems just a tad shinny) different, and compared to Red & Blue, seems more elasticy/springy to the touch & also at play .. Flat-hits, and Top-spins, with the Yellow, produce a distinct Click sound. Not so with the Blue & Red. The Yellow, I feel produces a higher-arc, compared to the other 2. For some reason, I find that my top-spins with the Yellow, produce a lot of side-spin (Could it be due a handle over-grip on the setup with the Yellow Sponge ? )... In terms of speed, I can't make-out much of a difference between the Yellow & Blue. (Could be due to the Blades) ... But, I certainly find the Yellow to be more bouncy/Springy.
The topsheet of the Red & Blue variants look Similar'ish .. Both have a mat-finish .. However, the Red seems grippier to me, and I can lift back-spins better with the Red.. Although, the Red is glued to a fast, Stiff/Hard blade, To me, it seems the Spinny'est of the 3. I find the setup with the Red, also blocks the best, with a pretty fast rebound (dunno if this makes sense to you guys) . The setup with the Red also seems to produce a lower arc, when compared to the Yellow & Blue.
My Order of preference is Red, Blue, Yellow
DiSCLAIMER : As I've mentioned earlier, I've always plays with these rubbers on significantly different blades Blue on an All+, Yellow on a Hinoki Off- blade, and Red on Stiff/Hard fast blade.. .. I've never played glued the 3 rubbers to the same blade..