Cream dwarf hamster with blue harness

I lost my cream dwarf hamster named Niko yesterday around 3pm after I took his exercise ball for a spin near the UD Library on South College Ave in Newark. He's tiny, about the size of a ping-pong ball, with soft cream fur and a white belly. The standout details are a blue harness with a tiny silver bell and a heart-shaped white patch on his chest. He’s shy and might hide in small cracks or under planters, especially if there are loud noises. I really need him back—he’s part of the family and holds sentimental value. If you spot him, let me know.