For marinade: Combine all the ingredients in a small bowl and whisk to blend.
For kabobs: Thread all of the vegetables onto skewers, alternating colors, textures, and flavors. If using bamboo skewers, wrap the ends in foil to prevent burning.
Place the finished kabobs in a 13 x 9-inch baking dish. Pour the marinade over the kabobs, turning to coat. Cover and chill for at least 2 hours.
Prepare a grill for medium-heat cooking. Remove the kabobs from the marinade, reserving the marinade. Grill the kabobs until tender, basting with the reserved marinade, about 10 to 12 minutes. Serve the kabobs warm or at room temperature, on or off the skewer.