W169 Rear indicator not working after bulb change

[Brigbeale]

Hi all,
I noticed that the rear indicator bulbs were more white than orange so I decided to replace it.
I removed the old bulb and although it was dark, replaced it with a newer bulb from my spare bulb box. It worked fine and I refitted the bulb holder in the cluster but wasn't satisfied that it was orange enough, so I replaced it again with a slight darker looking bulb, again from my bulb box.
This bulb didn't work so I thought it was blown and got another one and that didn't work either.
I got the original and refitted it, but that didn't work

The front indicator and door mounted indicator lights work perfectly, it's just the rear one which has seemingly packed up.

Any ideas???
Is there a specific fuse for the rear indicators?
I'm wondering if I pushed the bulb down too far and the metal case of the bulb has touched the live contact and it has shorted out the wiring

 

[Brigbeale]

Well - now I'm even more baffled!!
I've just gone out to have another look at it, armed with a torch and test probe.
Pressed the unlock on the key and all of the bulbs flashed in acknowledgement.
Thought 'Huh??' And tried again.
Again all bulbs flashed.
Tried hazards and all bulbs work fine.

I think the car is playing silly bu**ers for not having new bulbs fitted!!