These things should not rely on a complaint. Either the council do their own checking and apply any reasonable regulations to all equally, or if they have allowed precedents, should continue to allow similar without getting involved. The system is flawed and the council doesn't care, even though the ratepayers pay them to care and do the right thing.
The council can't seem to make up it's mind whether it's a complaint (nasty neighbour) to planning permission (possible lack of backhanders not suggesting they are corrupt but anything is possible)
Complain about all the other brightly painted doors, get them served with enforcement notices then form an action group to stick up to (stick it to) the council.
I love the door. Pink is said to be one of the more soothing colours.
I see the bathroom in the link...but no other rooms.
As she said, the Georgians loved colour...meaning new colours were being produced by synthetic means.