Possibly playing all the games with the same color might be to prevent people from copying moves.
Do simultaneous exhibitors always play White?

Possibly playing all the games with the same color might be to prevent people from copying moves.
You could copy a few individual moves, no more than that.

Possibly playing all the games with the same color might be to prevent people from copying moves.
You could copy a few individual moves, no more than that.
See Derren Brown beats 9 chess players simultaneously.
http://www.youtube.com/watch?v=evZmpsl3jI0
You can do the same against a higher rated player on this site in a "both games per opponent start immediately" tournament. The other player may report you for getting assistance.

Possibly playing all the games with the same color might be to prevent people from copying moves.
You could copy a few individual moves, no more than that.
There are cases where when different colors were used, players would copy the entire game. I'm not sure why you think only a few moves could be copied.
Ok, so you and me are boards 1 and 2.
Board 1 I'm playing black. The GM moves 1.e4 and moves over to you
Board two you are white and play 1.e4 he replies 1...e5
After making his round he's back at board 1, I play 1...e5 and he plays 2.Nf3
Board two you play 2.Nf3 and he plays 2...Nc6
When he comes around my move will be 2...Nc6
etc.

Possibly playing all the games with the same color might be to prevent people from copying moves.
You could copy a few individual moves, no more than that.
There are cases where when different colors were used, players would copy the entire game. I'm not sure why you think only a few moves could be copied.
Ok, so you and me are boards 1 and 2.
Board 1 I'm playing black. The GM moves 1.e4 and moves over to you
Board two you are white and play 1.e4 he replies 1...e5
After making his round he's back at board 1, I play 1...e5 and he plays 2.Nf3
Board two you play 2.Nf3 and he plays 2...Nc6
When he comes around my move will be 2...Nc6
etc.
It's simple. Get the games out of synch. The GM makes 2 or 3 moves before he moves on to the next game.
For example. the GM plays 1. e4 at your board and waits for you to move. say you play 1...e5. Then he plays 2.f4 and moves over to my board, where I play as white. I mirror the GM's move 1. e4 and he responds with 1..Nc6

why don't they play all their games as Black then? It's not like they need the additional advantage of playing white

Sometimes the exhibitor gives the players choice of color. I picked black in the game to the right hand side. I must've been leaning back when this pic was snapped.

If so, why can't they play half their games as white and half as black ...?
Alexei Shirov loses a few more games than normal that way while also playing higher rated opponents than some allow.
Shirov Simul at the Scarborough Chess Club +17 =6 -2
http://www.youtube.com/watch?v=35clj8Ap2pA
If a player copied moves Shirov might wonder why someone would pay to make a fool of themselves.
If so, why can't they play half their games as white and half as black, or all as black?