the rattle can gloss white shouldn't stand out more than your car...make sure you get the wheel super clean and oil/grease free before you start, a good degreaser will be best at the stage...scuff them with some scotch brite (after cleaning...don't just scuff the oils in) until they don't shine, clean again with soap and water, i leave of the more 'harsh' chemicals here to be safe unless they are specific PAINT PREP chemicals...or even just water will be fine, you should only be washing off sanding dust.

start with a light coat, don't try to cover the old color in a couple coats...the first coat should just be a light dusting, wait 4-5 minutes then build color/thickness slowly giving a few minutes between coats. dust the tight areas a little extra in the earlier coats to help avoid runs (paint too wet) later.

it can be done and look just fine...but be ready for touch-ups when you get tires changed.