There are 2 * 4 red chairs = <<2*4=8>>8 yellow chairs.
There are 8 yellow chairs - 2 = <<8-2=6>>6 blue chairs.
Total in the morning there were 4 red + 8 yellow + 6 blue = <<4+8+6=18>>18 chairs.
After Lisa removed chairs there were 18 - 3 chairs = <<18-3=15>>15 chairs remaining.
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