Wind power at sea

Went for a walk along the Cromarty coast this afternoon and got this blip of construction in the Cromarty Firth. In the 90s it was North Sea oil rigs, to day it is wind turbines. These are turbine jackets, for an offshore wind farm. They will anchor 114 wind turbines to the seabed in the North Sea, off the coast of Angus.  I don't know why they are painted bright yellow, maybe the manufacturers got a job lot of yellow paint?