Icon for Yellow Series tools
An example of an atmosphere colored with Sky Lemonizer
An example of land colored with Yellow Terra-Coloring
An example of water colored with Lemonade Seas
This is the Yellow Series of planet coloring tools.
The Sky Lemonizer colors the sky Yellow.
The Yellow Terra-Coloring colors the land Yellow.
The Lemonade Seas colors the water Yellow.
Acquiring
Three of them (Skies of Red, Purple Terra-Coloring, and Deep Blue Sea) will be given to you automatically if you choose the "I want to paint planets" mission from your homeworld.
The rest are found the same way as artifacts: by visiting a planet with yellow radar waves coming out of it, using the radar to locate the item, and then using your Abduction Beam to acquire it. They have the same appearance as terrasculpting tools, so you can't be sure what you will get.