Colored Glass

Colored Glass (aka Stained Glass) is any glass that appears to have a single colo(u)r that is not black, white, grey, or in between those. They are used for some checkpoints' entire glass (red), and on all bosses.

Checkpoints with red glass

 * Checkpoint 4
 * Checkpoint 8
 * Checkpoint 11

Trivia

 * In Low Quality, the boss's glass contrasts better with the checkpoints' gradient. This may help to defeat it.