I've been using a hodge-podge of neon colours for the odd thing here and there for a while, but since my upcoming Honey Pop collections use them a bit I decided to settle on a proper combination and upload it.
Included in the download is this image that you can either colour pick from or use the hex codes, and a palette file to use with Sims 4 Studio.
Oranges are difficult to make fluorescent, but all the other colours pop like all heck!
If you use them I'd love to see what you make!