the stx wheels are so plain. not ready to change wheels and tires yet so i thought the center caps . has anyone done this? any help thanks

 

You may be able to change center caps, but you have to be careful. An example is that the FX4 center caps will not fit the XLT wheels. I found this out when I bought an extra set of wheels, thinking I could reuse the center caps. Didn't work. Totally different size.
I don't know which will fit which, but you will have to do some homework.

 

2nd that. I have a couple of caps that were supposed to be replacments for my Lariat wheels. They are not.
Many different ones, and colors don't show well on adds on e-bay. The chrome color varies a lot. I think you would have to pull one of your caps, and go to a dealer comparing different ones. Might be a lot of work. I do agree the stock STX one's look 'OK' not great.
Chris