Meh...I'm kind of torn between liking it and just loathing it.
I guess it's because we've never seen her with this colour before, and it just happened so quickly, that it came as a "Woah!" for us. Generally, Japanese people with dark complexions like Rika (or even Asians in general with dark skin) can't really pull off the blonde colour, but she's kind of pulling it off...I guess.
It definitely looks MUCH better when it's styled though, like in the H!M caps. It doesn't look that wig-ish anymore when it's curled, or any other style they'll attempt with it. I also think they could have chosen a better shade of blonde too...