Good Morning John:
Welcome to the Forum. Apperantly UK uses different wiring and colors than we do in USA but I will attempt to give you the help you asked for.
It appears the red wire is used for a switch leg which means the switch simply breaks the flow of power (when its off) or completes the flow of power (when its on). Therefore, you probably will not find a red wire in the box for the power socket you have mentioned.
If there is only one each of the other colors, you can put a yellow wire-nut on the end of each one and put a blank cover over the box. If there are two of any color, tie them together with a yellow or red wire nut and blank cover. Two of the same color means the power is comming to the box on one of them and continuing to another box on the other.
Again, your color and usage is different which may throw me way off base. Make sure you turn the power off on the circut before you start and, when you're finished you can turn it back on for the 'smoke test'. If no smoke appears when you turn it back on, we got it right.