Not what I’d call “pink” … that’s what I would call the way FRZs and Class D are represented.
It is, as the layer legend says. Crown Estate Foreshore … more info here : The Crown Estates clarification! Foreshore & Estuary areas.
Lighthouse (and many other helipads, [most] hospitals for instance) don’t have any restricted zones around them. Their usage isn’t frequent enough or intense enough, to justify them. Just give them, and the airspace around them, a sensible amount of space … and keep your ears open.
Lighthouse helipads are very rarely used … for maintenance, mainly.