you should really put the best checkpoint to start the level from to find it

Playful Blue is the best one (not including Ultimate Blend)

I think it's actually 14 battles rather than 13 on that last one.

Just so you know, your guide is cited, but only at the garbage Fandom wiki which I am currently revamping. They also don't know how wikis work (they tried to make a redirect by putting "redirects from" at the top of the page and don't know how to add references)

ty

@Fresh_Knight Stained Purple and Purply Blank are the same thing, the latter is the display name for the former before you've unlocked it.

For those who can't find Hot-Headed Red since the guide doesn't explain where it is, follow the first set of downwards-moving platforms up until the screen scrolls and you'll find the room that the guide shows. Break the right wall in that room.

Thank you!!! Though I haven't played in a bit what is Stained Purple again?

This is a very good guide, but there are three pieces of information that are missing that are pretty important to know:

1: Fading Onyx's Damage multiplier is x2, while Ultimate Blend makes you only take 1.5x.

2: Purply Blank/Stained Purple gives you a Last Chance ability, granting you more damage and an auto revive at 1 HP on death

3: Fading Onyx also grants you free repairs at checkpoints, likely to counterbalance the Double Damage thing

4: Stained Purple, unlike every Palette not named Heroic Red, does NOT slash your Burst gain. You gain the same amount of Burst energy as you would in Heroic Red, making Stained Purple a straight up upgrade in every regard.

@X-O

The Training Room is above the Mission Room through the ceiling where the green machine protrudes out from.

You get there by Air Hookshotting the Small Platforms just above the Orange Mission Screen on either side to flip up to them or you can Jump off the wall and land on them(I always have Run on).
Standing on them, you can Double Jump up to the walls where the Green machine is and wall-jump the rest of the way.

If you're skillful enough, you can Hookshot the inside edges of the hole and attempt to wall-jump up.

Once you're up there. The right is the Training Room with the Fading Onyx paint. The left is the Boss Rush room where you can earn the Ultimate Blend paint.