Unless your Challenger has Brembo brakes, you have the "plain Jane" OEM gray calipers found on most passenger cars. There are two ways to dramatically improve the looks of your calipers and wheels. The first is MGP Caliper Covers. You can get these in a variety of colors, including ones with a Challenger, R/T Dodge or Mopar script. They sell for about $199 for a set of four and come in three colors (red, yellow and black). Here is the website: 2016 | Dodge | Challenger | R/T - MGP Caliper Covers A less expensive option is to paint the calipers with brake epoxy paint. A G2 Brake Caliper Brake System kit sells for $64.99 and comes in 12 colors. I used this product on my old car and the paint really held up over the years. Here is its website: G2 Brake Caliper Paint Systems: G2 Brake Caliper Paint System Set (g2usa.com)
I've had good luck with the MGP covers. They aren't cheap but are stamped from a fairly thick sheet of aluminum. They're not fragile but yes, they can be forced to bend. I bought these instead of painting the calipers thinking the smooth surface would be easier to wipe clean. I take them off for the winter months. I don't drive a ton of miles with the Challenger but I apply a coating of ceramic sealant when I put them on in the spring and (honest to God) I never had to clean them all year long, April - November. I have a set on my daughter's car and got the same results, she puts on about 10K miles per year.
I have got good results with regular enamel paint as well. I have even used $1.99 WalMart paint. I was surprised that I never had issues with it flaking off from heat. About once a year I would give them a touch up spray just to brighten up the color. On my Challenger SXT, I used Duplicolor metallic red and it is holding up great as well.
They turned out nice. I've also used regular spray paint on calipers in the past and never had the paint flake off. How often do you need to clean them during the year?