Riko's tie (I apologize if that isn't what it's called) looks more yellow to me. Maybe she's wearing Yoshiko's spare uniform? That would be kind of interesting too. Also I really love the background. With context they'd probably be on a date which is a nice thought.
I get it now why of all the pairings in Revue Starlight, KuroMaya is the topnotch. I'm more of Hikari x Karen pair but these two have lovely and strong sexual tension for each other.