I'm not sure how plausible this is, but using the shader I realized it was jarring seeing the difference between the translucent rain and the opaque bright blue particle splashes on the ground, and I was wondering if it was possible to incorporate a similar effect to the rain for certain water related particles?

it is very difficult to narrow down what particle is what, as there is no way to identify them except using their color with the shader.
if i do some rough color thresholding stuff, other particles with similar color would get the effect, and if the resourcepack changes the color, it could ruin it all.

i see, fair enough