Houdini Rainbow Particles - Redshift Scene File (Simulation Cache Included)

Fully lit and textured scene. Cache included so you don't have to waste 3 hours simulating. 

The file's HDRI can be found for free at: https://hdrihaven.com/hdri/?c=overcast&h=whipple_creek_regional_park_04

Only thing you need is to add your own roughness map for the collider shader.