This was a great little puzzler! I really loved the concept of mixing colors and using the waterfalls to reset the torch too, very nice touch. I played most of the game without reading the description (except for pressing E to light the torch) so it was pretty intuitive.
I couldn't figure out the 2-torch mechanic because I couldn't see the places to put the fire next to the door. I was going to give up but knowing that the waterfall was there, I knew the solution had to be within that room so very good design!
The lever was also nice but very hard to see. I got stuck at those 2 parts and some sign-posting would've been great there.
I also would've liked the fire lighting animation to either take less time or is skippable.
Overall, very nice game! I could see this being a full-release!