The color difference is very subtle - essentially it is black. You have to see it in bright light to notice any difference in shade. I probably shouldn't have mentioned it but I did in case you are completely OCD about the color of your components. It's not something most people would notice.
Regarding sound differences, you should know that I'm one of those guys who can't hear any difference in interconnects. I'm sure that some people hear large differences between two CD transports but I'm not one of them. I've compared the two transports through the same DAC on multiple occasions and if there is a difference it's not significant to me.
As I mentioned earlier, I have put together my endgame digital rig and there was no doubt in my mind that I was going to buy the CD3 instead of the CD2. I wanted to be comfortable that I had bought the best sanely priced transport I could find. If I had bought the CD2 I didn't want to always wonder if I would have been happier with the CD3. I have over 4000 CDs and I'm committed to the format. I'm pretty sure it's the last transport I will ever buy (along with the 701T). The Jay's is so nicely made and works so smoothly that it's a pleasure to use. That's a very important factor to me.
Good question regarding the LTA DAC. It's a NOS Ladder DAC which does not use a filter so I would think that oversampling wouldn't make any difference. If you decide to get the CD3 it will be interesting to try it to see if oversampling makes any sonic difference.