I was actually inspired to do this by getting confused over the hair colour of the different Elves, believe it or not ("Wait, which one of them is blond again?"), so this is a kind of recognition chart. Like they issued in the Second World War for enemy aircraft, except this one is for Eldar. See if you can work out the other identifying features I gave each Elf... (Explanation is under the cut)
Miriel is carrying her knitting and looking utterly exhausted, poor thing.
Finwë, king of the Noldor, is wearing his royal robe and crown.
Indis is, of course, a pouty blonde trophy wife.
Ingwë is carrying his harp.
Elwë is wearing a grey cloak, of course.
His brother Olwë carries a sextant.
Fëanor has a cunning smile, and carries a craftsman's hammer. He is wearing the Silmarils.
Nerdanel - one of only four known Elvish redheads - is carrying a sculptor's tools and smiling cheerfully.
Findis has inherited her mother's pale blonde hair.
Fingolfin carries the sword Ringil with which he wounded Morgoth.
Anairë is an Elven women of whom nothing but her name is known.
Irimë is likewise barely mentioned in the stories.
Finarfin has his trademark golden hair. Like his brother, he wears colours that celebrate both his heritages.
Eärwen, the Swan-Maiden of Alqualondë, wears white with a nautical blue scarf.
First column: sons of Fëanor
Maedhros has his mother's red hair, and looks grumpy because his hand has been cut off.
Maglor smiles cheerily and carries his harp.
Celegorm is accompanied by his trusty hound, Huan.
Caranthir, swarthier than his brothers, looks annoyed.
Curufin has his father's eyes. His wife is unknown, but he has a son.
Amrod, a skilled hunter, carries his bow. He has his mother's red hair.
Amras is Amrod's twin brother, or was until his own father accidentally burned him to death.
Celebrimbor, maker of the Rings of Power, wears a blacksmith's apron and carries a hammer.
Second column: children of Fingolfin
Fingon carries the blue and silver banner he bore at the battle of Nirnaeth Arnoediad.
Turgon is dressed in white and gold. He carries the sword Glamdring, which Gandalf would later wield.
Elenwë is warmly dressed for crossing the Arctic pack ice. She is a Vanya, and thus blonde.
Idril 'Silverfoot' goes barefoot, which she was famous for.
Aredhel, the White Lady of the Noldor, carries the bow she used for hunting.
Eöl the Dark Elf carries the black sword Angainor which he forged.
Maeglin is angry because his cousin Idril won't date him. He carries a miner's hammer.
Argon wears decorative rather than practical armour, and looks miserable because he was killed in the first battle the Noldor fought in Beleriand, and wasn't even named in the published 'Silmarillion'.
Third column: children of Finarfin
Finrod has his father's blond hair, and is all in gleaming silver because he's such a great hero.
Angrod. What can we say about Angrod? He didn't really do anything, and then he died.
Edhellos is just as generic as her husband.
Orodreth wears darker-coloured armour because Túrin Turambar was a bad influence on him.
Aegnor looks pretty much like his brother Angrod. He's keen-eyed.
Galadriel! We all know who Galadriel is. Yes, she's carrying a mirror, for reasons.
Celeborn has silver hair. I resisted the temptation to make reference to his Quenya name.