I made this at a summer camp when I was like 12. It adds the following items:

• Rainbow: a crafting ingredient that falls from the sky when it rains
• Rainblow: a slightly rarer crafting ingredient that also falls from the sky when it rains
• Rainblow Tools: exactly what they sound like (made of rainblows)
  • Pickaxe
  • Sword
  • Hat (helmet)
  • Hoodie (chestplate)
  • Pants (leggings)
  • Shoes (boots)
• Rain Bow: a bow made of rainbows (in place of sticks)
• Rainblow Arrow: an arrow made of rainblows (to be used with the rain bow)
• Rainblow Block: exactly what it sounds like
• Rainbow Wool: a wool block that includes all colors (crafted with rainbows or with a white wool and red, orange, yellow, lime, light blue, and purple dyes)
• Rainbow Wool Stairs: exactly what it sounds like
• Rainblow Forcefield: an item that, when right-clicked, generates a force-field around the player (crafted with 8 rainblows and one obsidian)
• Rainblow Staff: a wand that can be drawn back and released to fire a fireball. Draw pack part way for a small one or all the way for a large one (crafted with 3 rainblows and 2 quartz)

This mod is only ever provided AS IS. I neither plan to update this mod nor to support it. I made it the better part of a decade ago and have since then only touched the jar to edit my name in the author line.