Rainmaker

The Rainmakers are Decepticons in the cartoon portion of the Generation 1 continuity family.

All the colours of the rainbow, except for one...

The Decepticons known colloquially as the Rainmakers are part of Shockwave's forces on Cybertron. Each one is a Seeker with a bright, single-color paint job. (The green member, Acid Storm, did find a more exciting palette.) They retain their original Cybertronic "tetrajet" alternate modes.

As their name implies, they can make rain. Acid rain.

Fiction

Generation 1 cartoon

When a group of Autobots (and Chip Chase) journeyed to Cybertron to fetch a cosmotron for a wounded Optimus Prime, Megatron sent the trio to make things difficult for our heroes with some acid rain.

Guess what? They lost. Divide and Conquer

Trivia

File:Redrainmaker.jpg

...there it is!

• In one close-up shot of one of the Rainmakers firing on the clouds above Cybertron, the jet appears to be solid red, not one of the colors shown in the trio. Make of this what you will.

• The acid rain only affected the Autobots. Chip Chase was utterly unharmed. Make of that what you will.
  
  
  From Teletraan I: The Transformers Wiki, a Wikia wiki.