re: Blur - not the rock band...
This picture reminds me of a shoreline of a lake that I visited last summer.
There had been a metal smelter on the shore sometime in the past and there was some slag and rust in the sand left over from the operation, the color of the slag and the rusty sand was very similar. Even the "shoreline" between the darker blue (water) and the sandy "shore" have similarities.
I still do not understand why there could not be liquid water on Mars, especially if the water contains calcium chloride or some other such salts.