Color-wise, I guess it all depends on what you like and prefer. Everyone is entitled to their own opinion, and it's your money. Do what you like with it! =] I have sky blue and black, and my pad is sky blue, my woof boots are sky blue and black, my splints are black, my bell boots are [sadly] royal blue, and my tack is all black. Black breeches with a sky blue stripe down the side, black vest, sky blue polo. Blue helmet, black gloves.
So I guess we're coordinated to the T, but not intentionally, not at first. I got the breeches and the tack before I started eventing, as well as the pad, so I guess my family [via gifting] picked my colors for me! =]
As for braiding... I do yarn and tie. I tried rubber bands, and it just doesn't work for me. With a seam ripper, it takes me at most five minutes to take them out, and I love the "wild n curly" look Zip ends up with out on XC. ^.^ I think a neat mane, cut straight and short, would work for the lower levels, but for Zip, his mane absolutely will not stay on one side no matter what I do. Soooo... yarn it is. =] I've gotten pretty darn good at it- it looks neat, tidy, and it only takes me an hour or so.