A Question About Colt's Anodizing Through the Years

[BH321]

Why did Colt choose to change the color of their anodizing over the years? The XM15s and M16s I have seen tend to have a dark grey anodizing, the SP1/SP2/M16A1 series rifles tend to have a lighter grey, and pretty much all Colt rifles I have seen from the 90s onwards have been black. Was it a government decision or Colt's and what was the rationale behind the decision?

[rljatl]

I just bought an M16A1 kit from SARCO. After using a degreaser on it, the receiver looked light to medium grey. After wiping it with CLP, it now looks olive grey and matches perfectly the original Colt barrel I bought for it.

So, before Colt switched to black, maybe the shade of grey has to do with how much oil has been wiped on it?

[Leaveammoforme]

Isn't the color just a dye? Weaker or stronger solution will make it lighter or darker. Anodizing alone will leave a yellowish tint if any color at all.

I know this is correct info for a level 2 home brew. Not sure if level 3 (mil spec) follows suit though.

[SeaDonkey]

Don't forget purple…..