-77.65% is the change from 255 to 57
Calculation steps:
[( 57 - 255 ) ÷ 255] x 100 = -77.65%
Formula
Percentage change = [(57 - 255) / 255] x 100
Subtract the new number by the original number
57 - 255 = -198
-198 ÷ 255 = -0.7764705882352941
-0.7764705882352941 x 100 = -77.65%