200% is the change from 85 to 255
Calculation steps:
[( 255 - 85 ) ÷ 85] x 100 = 200%
Formula
Percentage change = [(255 - 85) / 85] x 100
Subtract the new number by the original number
255 - 85 = 170
170 ÷ 85 = 2
2 x 100 = 200%
Example