On your config.h or config.def.h, replace the colors array values to:

// config.def.h
static const char _colors[][3] = {
					/*   fg 		  bg 		 border  */
	[SchemeNorm] 	= { "#c79bff", "#240041", "#444444" },
	[SchemeSel] 	= { "#00ffb7", "#900048", "#900048" },
};

Rebuild your dwm fork

sudo make clean install