So what if you're plain and boring? If you're comfortable with that, than be that way. It's not up to others how you present yourself.
If you want to spice up your wardrobe, go with bright spring colors (it is summer after all). Stay away from plain denim, lots of the same color, khaki, and plain shirts. There are shirts out there with tons of color splashed into them and all sorts of interesting skirts, capris, etc. Pick up a magazine and brush through a catalog.
EDIT: And I just realized you might be talking about your HA instead of your actual wardrobe. If you are hurting for ideas, there is a whole forum devoted to how HA's dress themselves. I suggest you look there.
Maybe try a different style with your hair. Just parting mine on the side instead of the middle made a big difference for me.
Try some colors? Accessoires? A new hairstyle? :)
You can always try and dress like this. If that's not the opposite of plain and boring, I can't help you out, sorry. :(
xD