Personally, I'd love to see a color simscreen. However, while it's an interesting concept, the biggest problem most likely isn't the screen itself. The microcontroller required for such an application costs nearly as much as the screen, not to mention added firmware complexity.
I'm wondering whether the current simscreen gets all pixels pushed to it every update, or only the data. With the color version, you'd have to upload a template to the memory of the color simscreen once, and send only packets with the required sim data while it's in operation. Otherwise, both the bandwith and CPU time required to render in software to an external display would not be worth the trouble over a second graphics adaptor with a simple VGA monitor attached.
One of the problems with both the memory and controller(s) required for processing and storing the graphics is
SMD soldering. All current symprojects products use through-hole components, easily soldered by hand. SMD however, requires expensive machines to produce if done in house. It can be outsourced, but compared to through hole assembly it'd still be expensive.
The only "standalone" color display currently on the market costs €412 in addition to a €227 controller. This system uses an SD card to store designs, which could be an alternative to onboard memory. However, mechanical assemblies like the card reader aren't cheap either.
I'd love to see a cheaper alternative to a €640 product. But I think it would require both expensive engineering and manufacturing to come up with a solution altogether, let alone a cheaper one.
