but thats irrelevant to the craftworld.
the shrine colors dont correspond to the craftworld they are from in the lore.
or do they?

Nope, the shrine colours should be different than the craftworld colours ^^
Just edited the previous post a bit for how I feel about seeing a Dire Avenger in Biel-Tan colours fighting alongside a guardian Biel-Tan colours... (hint: heresy!)

I think its fine for the Aspects to follow a different color scheme most of the time while yes the colors of the Eldar do give them that unique look a smart army wouldn't be using a color that stands out and says... Here I am shoot me.

but then there is basically no difference from craftworld to craftworld.
not even cosmetic--just in a little symbol.
thats..to say the least,

*clears throat*
fucking stupid

tell that too..
*scratches head*
every single craftworld eldar ever to exist.
and the harlequins.

Aspect Shrines are not quite big and they know eachother. If an army knows who they are and represent, then why need much color difference? Is that not even more efficient?

Look between hatred of Space Wolves and Dark Angels. or Space Wolves and Flesh Tearers.

Now look into the rivalry and suspicion even between Eldar Craftworld.

If EVERY Aspect Warrior (i.e. All Fire Dragons) look the same, then they might fight closer and better together as they think of themselves as one united force rather than to fight 'with those asses from the craftworld we hate so much.'

but the eldar arent human. they dont need to be the same color to not fight.
they are prideful though--and they would want to make it clear from what craftworld they were from.

The craftworlds still have a difference, since a big chunk still use their individual colours.
Although yeah... most of them are guardians, but they still include warlocks and all other seers, as well as vehicles and autarchs.

but thats it. and thats only one class.
warlock/seer.

One would imagine that this would be done with colours and heraldry. Should not be too difficult.

Your words are wise, but you must consider that we are, as is to be expected of a people so great as ours, proud.

Proud of who we are. Who we belong to.

Is it not then, indeed, more than reasonable that we should wish to carry on us the colours and heraldry of our own Craftworld?