All of my friends have told me that making a four color edh is imposible because there are no 4 color generals. But what about Reaper King ? Couldn't I just use 4 colors and cast him with the two colorless instead of the 5th color of mana? And if i did, how well would this work?
I don't see why you would use the two colorless when you have a 5-color deck, and therefore can use all five colors! Darksteel Ingot , Terramorphic Expanse and its ilk, Gilded Lotus , Solemn Simulacrum ... there's tons of color fixing for a five color EDH, even if you don't actually want to use all 5 colors most of the time.
Yes, you could. Technically it would be a five color EDH deck, even if you only used four of those colors.
Technically they aren't Legendary, but the Nephilims have traditionally be used as 4-color Commanders in casual settings. Ask your playgroup if they'd be okay with you creating a deck around Ink-Treader Nephilim , for example, explaining that he would be treated as a Legendary creature for all purposes in the game.
I can't imagine why they wouldn't let you.
i use Cromat as a general for my wolf/werewolf edh deck and have only a splashing of blue and black in case i need to cast the general in emergencies but the reason it needed to be black and blue was cuz of Garruk, the Veil-Cursed Flip being black the git and also Fable of Wolf and Owl having blue in it even though i cast it pure green lol it can work nicely although i have 2 5 colour EDH decks and they both work great, very expensive land but they work well lol