Michael,
I suspect that your glasses are now starting to "rust" - have you seen an optometrist lately? 
I can see the same green in the center as that shown in our technical manual:
Thank you for the insult, Alfred. It looked to me that you were using a can of spray paint in the center of the wheel covers as some kind of sample. I did not realize that the color there was original, and that you are only trying to match the cap to paint that is already there. To have rust around the edges and some kind of color in the center seems interesting.
If you have a sample then, why is this an issue? Why don't you take the wheel covers to a reputable body shop; they will have a paint match system, and be able to mix up the paint for you quickly and accurately. It will be of better quality than you can get out of any spray can. They will give you matching primers as well, and may give you sound advice (which you might heed) on how to properly clean, treat and prep such rusted steel. If you have no relationship with a body shop, any auto body supply house (where many buy their paint) will have the paint matching systems, but probably won't be able to give you experienced advice. If you have none of these options available, Alfred--send it to me. I have plenty of these options available and will be happy to get the paint for you, even if you do insult me. You can take the paint and put it in a Preval sprayer or buy a sprayer that you pump up at Harbor Freight. Or, if you want a proper job on these, leave it to the pros. Without masking it is pretty easy for them.
My experience indicates that the best possible paint job you'll get out of a spray can will be something akin to a mediocre or bad professional job. That's why auto body shops and repair shops don't use spray cans. Thank goodness I've never seen Mercedes paint in Dupli Color. Goodness knows what we might find out there!
Are these wheel covers worth salvagiing? What condition is the chrome in on the front? Dents, scratches? There's a lot of work to be done on those backsides to get them ready for paint, as I'm sure you know. Sounds like you are trying a better than Concours quality job since even at a Concours they don't remove the wheel covers.
My old wheel covers had no such evidence of any paint by they way, just lots of rust. The dents, scratches, etc. on the front made them substandard, and replating would have been ridiculously expensive. And later I would have had to find out about painting the backsides, too!
