Fall colors of tree different each side, split look

In spring and summer my Japanese maple is the same green all around. But when Fall comes the tree looks like 2 trees in one. One side always gets yellows and oranges, while the other side gets deep purple, almost black, and reds.

Every year the colors are the same and the tree looks split in Fall.

Is it possible my tree is 2 trees grafted into one? But why in summer do leaves all look the same?

Whatever the case we get great comments yearly by people if how awesome the tree looks each fall.

http://www.preservationtree.com/blog/reversion-of-grafted-trees#.UncRQj9OnFo

that is why when you see a tree reverting clip off the offending growth - I see that happen with jm butterfly the most and a few others.

from your picture the leaf shape looks different as well. with one that large it might be too late to fix the problem and live with its split personality.

The tree was given when I was a little kid, my parents knew nothing about tree care. It's over 20 years old so if its from grafts taking over its too late.

I'm not complaining I think it looks cool!

If it is 20 years old it may or may not have been grafted. If grafted you may have one rootstock tree from below the graft and one grafted tree from above .. But this is all conjecture as always a photo of tree with a second photo of the trunk and lower branches is necessary. I doubt it is reversion over time it takes the whole tree over..and occurs most often in variegated trees.. If not grafted it may have been just two seed grown trees grown together. But as always asking a question like this without visual help is just not the way to get answers if any can be gotten. D=San

That tree is just beautiful and surely a conversation piece.