Thanks Guys for all comments
As some of you said, the grey color CMC 045-C
is the ultimate for this model and I'll explain my point of view.
The original color of the model is the silver one for it to be a continue
of the MB Silver arrow line but....
Because the SLR has some add-ons on the car that are plain aluminum color metal
such as the air intake strips on the front hood & on the front side air intake.
It seems to me that in the silver color model is not projecting this air intake shape as it should.
Maybe in the 1:1 car were the scales is a bit different and the light & shadow reflect different on it, might seems better.
I decided on the grey color for that reason and for it seems to me slightly metal blue, that is a color I like very much.
For those who want more details you can PM me