There is a color position Key on the cartridge that indicates to the printer that the correct color cartridge is installed. This is a simple plastic piece attached to the side of the cartridge body and has no mechanical or electrical components. I wouldn't suspect this to be the culprit, if you were using this cart previously without problems.
It sounds like you started having problems with the LLK cart after you had successfully started using it? From you post, it looks as though you replaced the batteries in both trouble carts and it only fixed the G. Are you certain the battery you used to replace the LLK chip battery was fresh?
The only possibilities here would be
1.Out of date battery
2.Chip not re-installed flush on cartridge chip holder after battery replacement creating a bad connection between chip read sensor and chip
Please explain what kind of error you are seeing on the printers display after you double check the above suggestions.