i like the lime green scarf idea instead of switching to a darker green. i think you could also use a hand held item and some arm items. possibly pink ribbons from the valentines event and then the green witches arm things. that would probably work nicely. and i think you need a little lime green around the neck. although im not sure about a hand held just yet. let me go look and ill edit this later.

Edit:
Large Medicine Filled Syringe, Orchid Fan or maybe the White/Pink Spring Breeze Umbrella. there are some suckers that might work too and maybe the Dango, Green Grapes, Ivory Cream Fairy Floss, Strawberry Cordial or Strawberry Cream Lolly.
and thats only going through 2 stores. so take your pick really. depending on what your going for, each have an application. i like the lean towards creepy with the syringe, but you might like the umbrella best.