The thing is with toyota OEM coolant, this thing is reddish and pretty greassy.

I've had a few leaks on mine, and it'S very hard to tell if it's PS, transmission or coolant in small quantity. Coolant gives the same oily feel as the rest, when taken from the ground.

I would first check your coolant level, if it's below level, be pretty sure it's a hose leaking. Could be MANY things, as hoses are getting older on this. Had a few hoses leak over the years, for no apparent reasons.

Next, look at your transmission fluid, and if it's that on the ground, you can often ''smell'' the bad smell of it. You don't want to go low on coolant nor on transmission level. PS level going too low, at the worse, you'll lose power steering and use power arms to turn, and have to change a pump, much better than replacing a trans or an engine.