You didn't say anything about your growing conditions, or skill level, but I have seen both Hibiscus acetosella and Acalypha wilkesiana successfully grown as house plants. Both can get large and have the appearance you are requesting. I would not list them under easy and forgiving indoors, though.

Your plan is a little like getting involved in a water polo game before you know how to swim. Trees as decorations aren't like a 2D painting. They are actually 3 dimensional in form with the added dimension of life that must be sustained if they are to remain decorative. There are dozens (hundreds?) of trees that have have the potential to outlive anyone that might read this post in 2016, plus their progeny if cared for properly. The question is, are you willing to make the effort to learn what it takes to maintain the vitality of your decorations, or are you willing to keep buying trees to replace those that decline if your plan isn't fruitful? Just some things to consider.

A good place to start.

Al

Haha, I never said I was going to get a Japanese Maple - I said I considered it before reading about it. I just wanted to know what other plants there are that might give the same effect. I have a ton of plants and I take care of all of them properly; they aren't just decorations to me. All of my plants are thriving.
Temperate climates are mild, not cold. But thanks for info, everyone.

The point about the temperate climates where JMs hail from is that they do have a winter, including freezes, even if it might seem mild compared with continental winters. The temperatures are very cold compared with indoors.

Many house plants have reddish tints but they don't necessarily look much like trees with Autumn foliage. Others have given you some names. If you Google coloured leaved house plants there are a lot of other examples.

Temperare climates are mild, but they have cold spells. Some trees need a cold spell to continue with their life cycle. Apple trees for example need a cold winter in order to produce the flower spurs that will later bear fruit. Just an example. I live in england. I know about temperate lol

Since you don't seem to be hearing that trees don't grow well indoors (in ordinary bedrooms w/ no special conditions for them) you could probably benefit from lots more reading.

As to your decor question, you'd probably do best w/ silk or plastic for the effects you desire.

Lena

The major reason Ficus benjamina is so ubiquitous is that it's the only commonly available indoor plant that looks like a "tree" in the sense of having a trunk and a canopy with lots of small leaves. So a lot of people grow it because they want that look, although it's not one of the easier house plants, and still needs a relatively high light level for an indoor plant. Doesn't come with colored leaves though.

There just isn't a whole lot else to choose from if you want a "tree" like look. Ming aralia, maybe, which indeed looks a little like a Japanese maple and fools some people. Some other good suggestions above. Abutilon does look a lot like a maple but it's a very broad, large leaf, not delicate like Japanese maples, and it needs high light. Bedrooms can be tricky because they generally don't have high light conditions. Maybe evoke the trees or forest via wall decals, and have smaller plants around (ferns?) to evoke the understory? :-)

Parsley has some very good creative suggestions for "bringing nature in" to give the look that you want. Unless you have the luxury of very large windows, a sun-room, or conservatory, just understand that an actual tree indoors might require lots more work (light setups, etc.). How much time do you realistically have for such an endeavor? Plants need light to thrive, and in the case of trees, a dormant or cold season--otherwise, you may just have to plan on replacing plants year after year. Maybe take a second look at tropical plants that can mimic the autumn look.

Another example of an indoor tree is Paquira. Known as the money tree it has large leaves on a long stem and is often braided. Number 5 on this page

http://www.sheknows.com/home-and-gardening/articles/839339/6-houseplants-you-can-keep-alive