Eldritch altars: red or blue?

hi, im having this question since a while, what is the difference between red altars (searing exarch) and blue altars (eater of worlds)? they give same rewards? or different? the only thing i noticed by myself is that the red altars are more dangreous than the blue ones, but dont know what is better for profit

For profit they are the same.

I'd recommend choosing a side based on the type of damage you deal: if you deal cold/lightning, go for the reds. If you deal fire/chaos, go for the blues.

If you are CI, it's incentive to go for red.

In short, pick a side based on downsides: pick the set of downsides you can manage easiest, because most likely you will not read them before clicking the altars.