Hey Davy!
Well, I don't know that you need to worry about the color bits so much, if you have other things set up right.
1. One needs to choose ONE breed, and choose the ONE that you want. Choose the ONE whose history excites your imagination, a breed that you want to tend and watch develop. The importance here is the ONE. This doesn't mean that there will never be another one to add; it just implies that you'll learn the ropes more thoroughly and feel more confident if you don't have more than one breed. If one begins with multiple breeds, the chances of failure or, at least, extreme delay, are much greater. Nothing says, "I'm going nowhere" like a laundry list of breeds. This is a lesson that many of us learn the hard way. However, when we get down to one breed, to which we're committed for the long haul, the game changes drastically.
2. Find a mentor. A beginner CAN breed stock up. It requires a whole lot of reading, SOP memorization, and the attending of shows. Still, you really need a mentor to whom you can direct your questions, someone who's patient and someone you feel confident obeying.
3. It all comes down to facilities. The rarer and less perfected the breed, the greater the need to hatch in number and raise out in number. It is usually the latter that is the difficulty. One needs to be able to raise out enough birds in good condition in order to be able to cull later on. It doesn't really matter if there are a lot of points to consider. Perhaps one would benefit from developing a check list, sort of like a score card. Have it on your computer and then, on days when you're going to go over your stock, print one out for every bird you intend to assess. Afterwards weigh out the pro's and con's of each fowl. If your mentor lives close enough to go over your stock with you, it's a real help.
4. Stock is often difficult to find in the form desired, but that doesn't mean it can't be found. It's often more easily available in the fall as opposed to the spring. If stock for one's breed of choice won't be ready until the autumn, it just takes a little patience. If such is the case, perhaps, you can use the spring and summer to raise out some heritage breed hatchery cockerels to get used to the various stages of culling and slaughter before digging in with quality stock in the fall.
PS: Going along with points 1 and 3, you need to have an idea of your breeding rhythm. Clan mating is pretty cool. One needs adequate breeding facilities for the families, or clans, that you'll develop. This doesn't necessarily mean huge numbers, just diversified families. Four clans is a safety number for me. For other breeders it might be different. Let's name the clans A, B, C, and D. Each clan needs a pen. All clan A females are in the clan A pen. All clan B females are in the clan B pen, etc... Develop a toe-punching system, such that each clan has its particular toe-punch, and, thus, there is never any confusion over who belongs where. Cocks can go anywhere save into the breeding pen of their own clan. Thus, a clan A cockerel is never at stud in the clan A pen. A clan B cock is never at stud in a clan B pen, etc... One can see how starting with two trios would be great for a system like this. With two trios, one has four hens; name one Pullet A, the next Pullet B, the next Pullet C, and the last Pullet D. The daughters, granddaughters, etc.., of each original hen go on to form a clan. The sons, grandsons, great grandsons, of the original females are never put to stud in their mother's clan pen. This will lead to maintaining a significant amount of biodiversity which will help to preclude the introduction of new blood. Introducing new blood throws everything up into the air.
It's matters like these that will spell success, and I don't think they're the things that we always think of at first: choose ONE breed and ONE variety of that breed, find a good mentor, have proper facilities, develop a proper breeding plan with proper identification. If these things are all set, choose whatever breed smacks your fancy. Some breeds will take longer than others to get to show quality--who cares. If you enjoy them, you have the time to be patient. Some breeds or varieties might be practically impossible to get onto champion row. Who cares? If you enjoy them thoroughly, that is your trophy.
Don't let all of the talk of difficulty psych you out.