Mark III Color Problem

[Infinite _Kaos]

I'm working on a project to try and get RGB from as many of my classic consoles as possible. I've started with a Sega Mark III since it seemed like an easy cable to make, and my SMS and Gen 1 are in storage. The cable works great for SG-1000 games (huge improvement in clarity and color), but Mark 3/SMS games are missing colors. When I use composite it looks fine. I've tried looking online for information, but the majority seems to be related to the Gen 1, since its a far more common system.

My setup is as follows:
Sega Mark III -> Custom Built RGB cable (using pinouts from http://dempa.jp/rgb/heaven/g_mk3.html) -> Extron System 4 LDxi -> Samsung 2333HD Monitor

Any thoughts? I'll grab my Gen 1 maybe later today to test it out. Since I've already got the connectors, I'll be working on an MSX2 and a Super Cassette Vision as well.

Here are some screenshots:
Star Force (SG-1000) RGB


Space Harrier (Mark II) RGB



Star Force (SG-1000) Composite


Space Harrier (Mark III) Composite

[viletim]

Place a 75 ohm resistor and 220µF capacitor in series with each video line.

http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm#megamstr