Coin Discoloration

Coin discoloration is a mechanic in B3313 added in v0.9. Coin discoloration, activated upon collecting several Red Stars, causes standard Coins to be randomly replaced by recolored variants with unique effects.

Purple Coins
Purple Coins remove one from the Coin counter, and will also damage the player for one health point. They are not found throughout the level normally, and can only spawn in enemies, crates, or boxes, presumably to catch the player off-guard. The chance of purple coins spawning increases proportionally to the amount of health the player has, with almost every coin being a purple coin at full health. They seem to have an unusually high chance of spawning in Pleasant, Pleasant Falls.

If the player has no coins when collecting a Purple Coin, the counter will jump to 99, a sound will play, and one life will be deducted from the lives counter, decreasing into negative values if the player has zero lives upon collecting it. Collecting Purple Coins is able to kill the player directly.

Green Coins
Green Coins add no coins to the coin counter and heal 3 HP, and will replace coins in coin rings and lines. These coins are the inverse of the purple coins, having a higher spawn chance on lower HP, and almost never spawning with max HP.

Orange Coins
These Coins are worth one to the player's counter, but heal for two health points instead of one.

White Coins
White Coins are worth zero coins and do not heal the player, and have a roughly 25% percent chance to crash the game upon picking them up. They have an even rarer chance to randomly spawn instead of another object, unlike other discolored Coins.

The actual behavior of white coins is actually very interesting when it doesn't crash the game, in the Discord Server, Benedani has shown that the white coin calls a random function, which could include anything from giving you stars, to even tampering with your save file, it basically acts like a single use Yellow Switch.

Motos Factory contains a guaranteed White Coin spawn in one room, which will lead to an unpleasant surprise if the player attempts to collect it.

Translucent/Outline Coins
Translucent Coins, sometimes called Outline Coins, are a type of Coin that rarely appears in stages with both a Blue Coin Switch and a Vanish Cap. when they spawn, they will take the place of coins from a Blue Coin Switch, and will remove the switch. upon picking up a Vanish Cap, they will transform from a dotted outline to a translucent blue coin, with the same properties as a normal one. Once the cap's effects run out, they will go back to being outlines.

Trivia

 * Coin discoloration is based on the mechanic of the same name found on the MIPS Hole Wiki. Many of the coin effects are taken directly from their page on coin discoloring.