I agree with Organic's answer about the ratio of materials in a compost pile. The trouble is, you're adding stuff whenever you've got it, like most of us do, and most instructions for 'efficient' composting are expecting you to have quantities of so called browns and greens all at once, and mixing them together all at once, then turning regularly, without adding anything else. Because a compost pile that's turned regularly, with the right moisture level and kept covered to trap the heat, becomes aerobic and hot, the resulting compost is ready much quicker - 3 to 6 months, depending on air temperatures where you are, and if you are able to turn the pile at least twice a week.
However, if you're adding stuff and turning it regularly, then you will inevitably end up with some parts composted down into blackish soil (that's what it looks like when it's ready), mixed in with other, as yet uncomposted material. Some compost containers have a door at the bottom on the front - this is to allow you to get at the bottom of the heap, which will be ready before the rest of heap, so you can remove what's ready and leave behind what's not. But usually, that sort of compost arrangement is aimed at creators of cold, anaerobic heaps, where its not turned regularly and just left to rot down quietly on its own, with stuff being added all the time on the top. After a year or two, the stuff on the bottom is, of course, ready for use when the top is still covered in fresh materials - cold anaerobic composting is fine so long as no weed seeds or diseased materials have been added, you're prepared to wait longer, and you're not intending to use the compost for anything other than adding back to the soil in the garden/yard. If that's not the type of compost bin you've got though, then you either wait till its full and all composted and then use it, or try to sift through and extract what's not ready for use after spreading it and replacing the uncomposted stuff in the compost bin.
Many people get round this problem (if they have the room) by having more than one compost pile or composter - they fill one up, then start the next, not adding to the first one any more, just turning it regularly, then when its ready, using the contents, and then start another compost pile in there when the second bin or container is full. If you have a lot of stuff to compost, then three compost bins works really well, but most of us don't have those sort of quantities.
You're not doing anything wrong as such - in an ideal world, you'd have masses of browns and greens all ready at once, 3 compost bins and the ability to construct the right sort of pile of compost in one go, but the world is not ideal, and for most of us, we do what you do. But however you do it, you will eventually get useable good stuff from the compost bin.
