The /particle command can be used to specify the color of created dust particles, the block and state from block particles, as well as many other parameters for other particle types, yet the minecraft:flash and minecraft:firework particles do not support a color field even though colored forms of these particles can be created by game. The included screenshots are from a modded version of minecraft, but only client-side mods are being used, and this does not affect the lack of these fields in the /particle command. The screenshots show the particles as created by the /particle command and what they look like when created by red and white fireworks, displaying the range of colors the game offers.