Chaos colour - make up your mind

Maligaro's bombs is vaal firetrap. It deals fire damage. Only his desecrate deals chaos damage (the one you can walk out of), though he fills the entire room pretty much with vaal firetraps if you walk away from him.

He's a real pain in Core map.

Chaos = green / purple.

Lightning = blue with tendrils on it

Cold = light blue / white with spikes

Fire = red with flames

Most of the time, there are exceptions like Malachai's tentacle attack dealing cold damage.