you need to make function for that. u cant use one line code to make it work. also make sure your code runs after darkrp loaded fully! setplayercolor might be work if you do hook function
also there 2 option
if you want to recolor just one job then you must add these code to job code that u want.
if you want to recolor every model then u need make this hook on another lua file or everywhere that not in job code