Celestron C11 - Colours, Years and Serial#'s

[srmnm]

Hi All,

Bought my first 11" OTA today. Its a Celestron C11.
Its used and Grey in colour. Pretty excited to get it going and do some imaging this winter.
Does anyone have any acurate information on scope colours Vs manufacturing year? I know the went from orange to black in the 80s/90s, but not sure what happened since. Did a little research but have not found anything conclusive. Is it possible to get any useful information from Celestron with the serial number?

Appreciate any input!

Thanks,
Will

[Merlin66]

My grey C11 purchased in 2009 has no serial number.
The design of the rear cell and standard coatings changed along the way.