I have a 1995 ford ranger 3.0 v6 with a five speed. I just bought is 4 days ago. It ran very well (considering ita age and mileage 160,000) but the second day driving it I heard a pop and the truck lost a lot of power and it started chugging and running very poorly. I read codes and there was a cylinder 5 misfire and a emissions purge valve. But the CEL was on before the motor started misfiring. So I changed plugs wires and the coil pack. Also noticed a brownish tint to the antifreeze. As if they're maybe a head gasket problem. There is still no change in the performance of the motor after new parts. Not that knowledgeable on cars so I need some help here.

 

What were the code numbers, don't guess.

I would pull out spark plugs #5 and #6, compare them.
Coolant in cylinder(head gasket leak) will "steam clean" a spark plug tip so it will look new, spark plug should have a brownish tint if all is well, although with new plugs it will be hard to tell.

Also before pulling them out unplug coil wire from coil pack, the 4 wire connector, we want no spark.
Crank engine a few times
Now pull out the spark plugs, make sure both are wet with fuel, if #5 is not wet then you have a fuel injector issue, could be pulse related or the injector itself.

And double check firing order on coil, I always goof up the 4 6 5 side, lol.
4 6 5
3 2 1

What base color is the anti-freeze?

Cold engine
remove rad cap
top up rad, water is fine
Start engine
if coolant starts to over flow you may have a problem with cylinder to cooling system leak.

A Cylinder has 180psi of pressure cranking and 1,000+ psi when running
Cooling system has 0 psi when cold, water pump is not really a pump, it circulates coolant but doesn't add any pressure to system.
So when cold a running engine shouldn't push coolant out of rad cap, it can rise for a second or two on startup but shouldn't continue to overflow.
What causes the continued over flow is the air pressure coming from cylinder leak, it is displacing coolant in the head with air and this pushes out coolant in rad.