Hello Santorin LO (by the way, what is your name?)
If I understand correctly you suspect you have a leak around the timing belt area - not the gearbox end that your picture shows. So the picture is just the "red water" accumulating after draining down under the engine, correct?
If this is, indeed, rusty water (I assume your coolant is a bit rusty) and you have eliminated it coming from a leak in any of the cooling water hoses, there are two additional possibilities.
1, It may be the fresh water pump is beginning to leak around it's shaft seal. This pump's shaft area is not visible without taking off the entire timing belt cover. That is, you really can't see it leaking; you just see some dripping below the timing belt cover. The shop manual says it must be replaced (it is not repairable without modifying the pump housing) and to do so involves stripping the entire timing belt end (easily done if you put the engine in the cockpit first). (About $200 for a new pump)
2. It may be you've got a pin-hole leak in the freeze plug (aka explansion plug) under the coolant water pump. Also requires stripping the timing belt end. (About $1 for a new plug)
If either is the case the leaking will become progressively worse, so you can monitor it to be sure exactly what it is, although you still won't know if it is the pump or the freeze plug until you strip the timing belt end first, put some coolant in and observe where it is leaking. As it gets worse it will start leaking faster and faster, to the point where your coolant level will drop and overheating will occur, so keep a good eye on it.
If it is one of these causes and since your engine is probably approaching 30 years old, replace the pump and all the freeze plugs while you've got the engine in the cockpit..
Good luck with it and let us know what you find.
PS - To help with the diagnosis you might try putting 2-3 oz of blue food coloring in the cooling water and see if your red turns blue.