If painting things makes them go faster, why dont orks paint an entire WAAAGH! red for hyper speed orks?

Oi' gitalowed o' dis git 'e don't e'en no the basicks of WAAAAGH!!!

Because without a basis for comparison their innate psychic abilities won't work. Remember, their psychic abilities only work based on what they believe. Think about it - if EVERY trukk is red, how do they know what the red trukks are faster than? Ultimately they spend more time among themselves than with other species so their best method of comparison is themselves. In order to know that red trukks are fasta, they have to have "normal"-colored trukks to compare them to.

The Waaagh doesn't involve colours dumbass.

The only reason why red trukks go faster is because mekboys subconsciously spend more effort on the engines of red trukks.

That's what you get when you have a species that is genetically engineered to do great technological feats without any kind of understanding what they do.

But black makes things dangerous.
A rainbow float won't be as dangerous as a hearse.

The red goes faster is literally THE example of how the WAAARGH works.

They don't because they're oblivious to their own ability to warp reality

...

Could you imagine how horrifying Orks would be if they understood that?

Don't you mean KRORKS!

Like said. Orks are green. Si if they are painted red, they cease to be orks.

Yes it's circular logic. Why? Because orks run on it.

But every ork is a psyker, so them believing that red goes faster actually makes red things faster

Bekuz, ya dum git. If all da orkz wuz red, den dey'd ALL be goin' faster, so NONE of 'em wud be goin' faster.

SEE DAT PLANET?

YOU CAN WAAAGH IT

They'd ride all the way to the imperial palace, steal the emperor on his golden throne and mount it on their best tank

But what if it was a pride float mounted on a black flatbed?

Single most powerful entity in the materium

...

Because the Inquisition said that never happened.

On a completely unrelated note, don't ever point your telescope in the direction of the Large Magellanic Cloud.

Rumors that one can see a red, wriggling mass with rockets attached midway between the galaxies has no basis on imperial reviewed reality.

Now, how many shootas can we strap to it?

BECUZ DA BOSS DON'T WANT NO YOUF GETTIN' TOO BIG FER 'IS BRITCHES WITH A TRUKK AS FAST AS DA BOSS'S YA GIT

GREEN IS BEST, 'N YELLA IS LUCKY.

There's a group of invisible Orks, how did they become invisible you ask? They painted themselves purple, and nobodies seen them since, because nobody has seen a purple ork.

all of them

Still not enuff dakka do

Could use a bit more dakka though.

Now hold on, we have to paint the boyz too, don't we? Otherwise it'll be the FLOAT that's all them things but the boyz would still be average boyz, right?

Oi, et sayz rioight ere in me rulez book dat da red paint job makez yer wagonz go faster

If Red is faster how can green b best?

t. Uruk Jadork Smizz, Ork Philosopha

green gives dakka ya groot,

Right, we paint the boys green, because green is orky, and therefore the best

Oi, why dun't we just paint our boyz wiv all da colourz?! Den we git all da powaz! Rainbow boyz ar' best!

cause green is best!

orks have lots of "magic" colors, red is for vehicles.

Uh, they DO. This is entirely what Evil Sunz's schtick is about.

PAINT IT RED!
Job's a goodun boss.