[ConnorMcLeod]

Not a major error, but
clamp( str_to_num( rgb[ 0 ] ) , 1, 255 );
should be
clamp( str_to_num( rgb[ 0 ] ) , 0, 255 );

IMO, change the color every 0.3sec is a bit too much, i suggest you to make 2 random colors mode, 1 when you set a random color every 0.3s as it is for now, the other one you pick up a random color, but for the whole time the message will scroll.