I make black and silver wheel centers that apply over the stock ones. They are on my website for $50 for the set. (I also have custom matching steering wheel emblems for $20) I will make 2 tone custom colored ones for $100 set. (like the black and orange for my car) You must be very patient with me on the custom ones though, it takes me a while to do them. Need to work them in around other jobs and conditions need to be just right (no humidity which is hard in GA even with the de-humidifiers) They usually take a couple tries as well before I get a perfect set. The doming resin is very finicky.
There are two styles of caps. Thick ones, used in at least '05 models and maybe early '06 and the thinner caps. Check out lotusgarage.com they list both of them. The thick ones do not fit on wheels that need the thinner ones. I found out the hard way.
I looked up the part the other day on lotusgarage, and it shows two parts. I emailed those guys to see which one was the one I needed. They did not respond, but I have an 06 Exige, and the center caps do not match flush (I do not have the base aka touring wheels).