Why is XTR stuff different colours ?

This may have been covered before but search function hasn’t brought up anything.

M950 seems quite consistent in colour apart from hubs. I’ve got a few sets and some are darker in colour by quite a bit? It isn’t fading.

M951/2 can be a lighter grey like M950 or can be darker too. I’ve got two pairs of identical STI units and the levers are different colours. Same for brakes - some are dark grey and some light.

Is there a reason?

I thought it was fading until I got a mech that was really light, the bits that don't see the sun were also the same.

Totally agree it can’t be fading as it’s same on bits that aren’t exposed.

Probably made in different factories and different countries too!

I've seen the same on the earlier XTR M900 / M910 rear mechs - always seems to me that M910 mechs are a lighter shade.

Yeah, had this when I bought a set of v brakes off here once. Different codes and slightly different colours. Had another single end which was the same as one of them, so paired them up and sold the mismatched one. As above, I reckon different factories and years. Could also be slightly different materials taking the anodising differently.
That's the trouble with anything other than black or silver. Seen the same with Hope stuff as well, Allegedly same colour but slightly different depending on material being anodised.