When Ruby dyes Ren's hair blonde and she takes the shower cap off, her hair is curly when it is almost completely straight as brown.
Ren has fairly dark brown hair, it would be rather hard to dye her hair that blonde because dark hair has a tendency to stay a bit darker than the shade of blonde Ren's hair was.
If you look closely, you really can tell that Ren's blonde hair is just a wig.
When Louis tells Lloyd "Meet me in the alley," he doesn't tell him which alley.