discolor (US) verb
or British discolour /dɪsˈkʌlɚ/ discolors; discolored; discoloring
or British discolour /dɪsˈkʌlɚ/ discolors; discolored; discoloring
Learner's definition of DISCOLOR
: to change in color especially in a bad way变色;褪色 [no object]
[+ object]
— discolored
adjective [more discolored; most discolored]