You have a bed of your own, so why shouldn't your cat? It's true to say that if you buy a bed or even several beds for your cat, he will probably still use your three piece suite, your own bed or indeed anywhere he wants, but you'll feel better able to move him on if he has his own special place to sleep.
There are all sorts of cat beds, ranging from the very basic to the positively opulent. You can try to fit one in with your décor but frankly, unless your wallpaper has colorful mice or paw prints all over it, you are probably on a loser there! The best you can hope for really is a color that doesn't actually clash with that of the room that the bed will be kept in. However, you should really be more concerned about how the bed will be for your cat.
Some of these cat beds are similar to dog beds but smaller, i.e. an oval foam filled cotton cover with a fairly rigid base and sides with a lowered part of the side for the cat to walk in (as if they couldn't jump over the sides anyway). These can be good as there is usually room for a bit of fleece or blanket inside, which is not only cozy for the cat, but keeps the cover of the bed a bit cleaner that it might otherwise be.
Another foam filled type of cat bed is similar to that described above but a little more like a traditional dog kennel in shape being completely covered over with a door shape for entry. Cats have a nesting instinct so some like this arrangement. Equally, if there are other animals or small children in the house, your cat may feel more secure with his own little "house" to retire to for peace and quiet. These beds can actually be heated but unless your cat is very old, this really shouldn't be necessary.
Most cats moult on and off throughout the year, so some sort of mat or blanket to put on their favorite chair can be useful. You can whip it off and hide it if visitors come and the furniture shouldn't be too hairy.
If your cat is a real heat junky, you can buy a sheepskin hammock type arrangement, which you can hang on a radiator. However, this won't be suitable for an old cat as agility is the key when getting in and out of these things.
Cats often like bean bags. This are an inner lining filled with small polystyrene balls with an outer cover that can be removed for washing. Placed in a corner or other warm spot, your cat will soon get to like this arrangement.
Unless you introduce your chosen cat bed into the house when your cat is very small, your cat will probably pay it no attention at all for some time. If he ignores it completely, try picking him up and putting him on the bed while you stroke him for a while. If this approach fails, try inducing him with catnip toys or treats. Make sure that the bed isn't in a thoroughfare and is somewhere away from draughts, maybe raised a short way off the floor.
If you have more than one cat, make sure that each one has its own bed. If they choose to swap around between themselves, then that's their business, but never expect them to share a bed, although they may want to, particularly sibling kittens.
If you want to make the cat bed multi-functional, buy one of those beds cum activity centers with a scratching post but be sure that you have plenty of room for it!