Red 3M reflective tape is very, very refective to cars at night!
I used a 1/8" strip on the side of a grey Burgman and it looked good on the dull matte painted scooter, like yours, and was a nice safety feature.
Pick up a roll on ebay, or some auto parts stores.
They (3M) also make a black, in tape, or panels which you can cut, which reflects white at night.
Stig