Icebergs in Antarctica a sometimes have stripes, formed by layers of snow that react to different conditions. Blue stripes are often created when cracks in the sheet of ice and water that fills and do not freeze as quickly as falling bubbles
When an iceberg falls into the sea, a layer of seawater can freeze salted side down. If this is rich in algae, it can form a green stripe.
Lines brown, black and yellow are caused by sediment collected when the ice crushed the field on the descent towards the sea.