Colored Flames will add seven multi-colored types of flame, which will give both positive and negative effects of potions that hit them players and mobs.
Colored Flames Mod for Minecraft 1.15.1
To make a colored flint, you need a regular flint and a certain object (a tear of gast, golden carrots, a spider eye, and others) that will determine the color of the flame.
Download Link: coloredfire_1.1.4