Prior to buying my candy red 2011 GTCS,I was seriously considering getting a performance white the dealer had on the lot,which was also a 2011 GTCS.
The bumpers had a definite shift in color,they appeared quite creamy compared to the white on the body,I live quite close to the dealer and wanted to swing by my house to show the car to my wife,which they agreed to during the test drive.
When I got to my house,my wife came out to check out what color I had in mind,and said to both me and the sales rep," really nice mustang,but why are the bumpers painted a different color"
That,my friends is why I went with the candy red.
I thought I was seeing things when I noticed the difference in both whites of the body/bumpers... but the comment from my wife told me it was quite obvious enough to "appear" like there was a second color....neither one of us can tell any differences between the color on the body/bumpers on the candy red.
My take on this issue;
I find it very unlikely that FORD would paint bumpers at a different location...different paint equipment,different die lots,pigment ect would be asking for trouble,and I'm sure they realise this...
Lets not forget that bumper paint has another chemical added to it,flex agent,which makes the bumper paint more flexable,without this addition,any little ding to the bumper will result in the "hard" paint to just crack and spiderweb.
Also up for consideration,the base material(s) are very different;one is steel the other is injection moulded plastic.
I discussed this exact issue with "Wayne " owner of Avenue Auto repair here in Toronto, (they cater to very high end clients with Benz,Aston Martins,Ferraris and the like,and he maintains that because of these exact changes (flex agents,plastic versus metal) these subtle variations will always be noticed,with lighter colors being more prone to visual change.
2011 GTCS Candy Red;Premium leather interior package, Remote start, security package, upgraded speakers, 6MT 3:55. 35% tint all around, Borla "S" axle backs, & clear corners.
The rest is all FORD