Basically, something fishy tends to happen when you try to edit the eye base.  When you create the new Sonic texture, the eye base becomes transparent instead of becoming the color that you wanted.  To edit the eye base, you need to instead edit Sonic's eye texture by filling the background with the eye base color that you want.

Example

You shouldn't be resizing any of the texture parts.  Also, if you didn't get the message, Marth's normal eye iris requires an indexed palette.

Funny how the Kirby textures have changed a bit since Melee.  Green Kirby had green feet in Melee, but is more like normal Kirby's feet in Brawl; likely done to be a reference to Plasma Kirby.

It would help if you included some snapshots.  Otherwise, no one can help you.

Not bad for your first attempts.

So if I made the mask transparent, it would show the textures normally?

Not too sure.  Not all +2 textures have transparency after all; certainly not Yoshi's egg texture, nor Ganondorf's hand texture.  You can always use the color black for the mask texture parts.

Don't tell me it's a nude peach.....
XP Idk what?

Not possible, considering that her dress has sleeves.

Thanks, it worked. But now the colours are neutral, is there a way to fix that? Sorry if I'm being annoying.

There is, but it depends on the colors that you're using for the mask texture parts.

Hmmm, I see... Too bad... =/
I guess the only one that can have more than 6 textures is Wario, right? Since he have 6 of Classic Wario and 6 of WarioWare...

You'll still be limited to 6 WarioWare Wario textures and 6 Plumber Outfit Wario textures since there can be errors when you attempt to place a WarioWare Wario texture (00-05) on a Plumber Outfit Wario texture slot (06-11) and vice versa.

I just indexed SonicBodyMask through Photoshop, but it still gets the erroneous colour message.

I think there was a topic on this in Help, but I tried everything listed there and it still didn't work.

Something tells me that you goofed up somewhere.  I tried it out myself and it worked.  Try filling the body mask texture with just one color to see if that makes a difference.

I had to dramatically drop the number of portraits that I use whenever that happens.  Today I had to go down to 120 portraits because of that.

It seems that the freezing is related to the Zelda, Sheik, and Pokemon Trainer portraits.

Index the texture in Photoshop or ignore it completely.

This guide isn't working at all.  I tried following these steps for Ganondorf's Final Smash, but it has failed horribly.

[G_asi]

From what I recall, Diddy does have a texture called G_asi.  That part does affect his legs a bit.  There's also the diddy_body_09 texture that you need to keep in mind too.

P.S.: Both of those textures require an indexed palette.

I don't know if you are aware of this, but there is a way to remove the black spots on Wolf's head.  You just need to remove the transparency on the back of the face texture.

Example