That white multi speedy is on my wish list too!i felt the same anxiety about my recent purchase of a White Multicolor Speedy. i'm getting close to 50 and thought maybe the Multicolor line is too young for me, or too dated and out of style. in the end i still purchased the bag because i really wanted it. and i have no regrets and love the bag.
if you want this bag than get it. don't let other people's opinions on what's in style or what's age-appropriate deter you from something that you want.