An Ice wizard generally can't wear Life equipment, which would generally be "shoes with a Life design", as you put it.
Your best bet would be the Bazaar. You can buy boots in your school (Ice) or generic (no school) boots, and you can pick the colors. Most Life equipment is Green with white or silver trim.
If you don't mind spending crowns, you can go to Eloise Merryweather, the Seamstress near Prospector Zeke in the Wizard City Commons. She has a wide selection of styles to choose from, and you can choose the colors you want. You would then combine the stats of the boots you have with the appearance of the boots you bought from her. Note that she charges Crowns for the stitching service.
A non-crowns options can also take the boots that you have to Darla Whisperwind in the Dye Shop in the Shopping District of Wizard City (it's the first shop you come to, with the paintbrush logo). Ms. Whisperwind can't alter the appearance of your equipment, but she can alter the color and trim for a fee in gold.