Healing and Harming potions have a different set of particles that sets them apart from other potions (particularly strength which is red, just darker) which I'm guessing is because they are instant potions rather than lasting effects, this can be seen when using a healing or harming splash potion.

The lingering harm/heal potions have a bit of splash with the proper particle, yet don't linger with this particle.

To recap, to test this:

1. Throw a healing splash potion
2. Throw a healing lingering potion