:roll: Best say nothing
Only seems to be one person with an issue on here
Just my 2p-worth, and none of this is to do with Sterling Grey per-se. All of this is on Sapphire Black metallic.
I am having my B3SBTfront and rear bumpers sprayed next week in my local trusted bodyshop to remove stone chips from the front, and an annoying supermarket trolley ding on the rear. The guys I use mix their own paint on site from the car code. They are also geniusses with car spraying, having part re-painted my Roadster S early last year :bow: . So, for the RS, they blended the paint through the adjacent panels (offside front wing and nearside door) as it was a full front end and bonnet refresh to rid her of road rash, and any slight colour differential at a panel joint on big, similarly shaped panels is very noticeable. However, I had the side skirts done too, and no blending was necessary between those and the panels above them as being plastic, a slight difference may have occurred anyway. As it is, everything matched perfectly, there are no paint edge lines, and the car looks as fantastic today as it did when new and there are no step colour changes. The guy who has bought the car cannot even tell it has been done, other than the car looks totally mint as a bit of a giveaway!
For my bumpers, they are not recommending any blending (they know my standards are VERY high, so if needed, they would say it). The bumpers will be removed from the car, stripped, smoothed and painted before being refitted. At no time will they compare the bumper colour to the rest of the car before they match it up...and I'm pretty sure I can say it WILL match 8)
The WORST colour cars to match are silver! I have experience of poor colour-match on 2 silver cars I owned, and every paintshop I ever spoke to about my silver E46 shuddered and told me how difficult it was to match silver paint without it being 'cloudy' at some point, effectively offering no guarantee that their re-work would be better than what I already had. My silver Astra estate workhorse has exactly this issue.....
I would guess you have either the wrong paint mix, or he's getting the metallic flake to angle the wrong way when applying the paint.