The 'Fountain Paint Pots' sound friendly, but they're actually boiling mud pits.
This is the approach to the 'paint pots' - through the Dead Marshes, outside Mordor - again walking on a boardwalk. Gollum says, don't follow the lights.
Just a gentle reminder. Some of the other warning signs elaborate further on gruesome ways that you'll be injured if you step off of the boardwalk.
And there they are, all of a sudden. Pine trees, then bam! Boiling pots of mud.
There is also a nearby geyser, to which the boardwalk will take you. The yellow around it are sulfur deposits.