The discoloration of ice in early summer in the Chukchi is an annual thing, I've posted about it previously and nobody seems to have an explanation. Sometimes the discoloration is striated, i.e. there are bands of different colors following the edge of the ice.
If one is familiar with ice, the first thing that comes to mind is that some sort of sediment has been deposited at different times on the surface of the ice, interspersed with snow, hence the striation and different colors.
Also another possibility is some sort of sediment that is evenly distributed throughout the ice, and areas that have seen greater surface melt show greater accumulation of sediment, explaining different colours but not the clear striation.
I've alwas assumed that these were airborn sediments, i.e. ash from wildfires, or more likely, dust from duststorms from the dry Siberian landmass, interspersed with snow.
Rod suggest that this might be sediment from rivers that is caught in the ice during refreeze which to me sounds interesting - but not very likely considering the movements of the ice, where most of the Chukchi ice originates above the CAA.
Image from June 5, 2016. Wrangel Island to the right.