......
are these new crossings legitimate?
...
There appears to be no mention of such folly in The Highway Code. Government road and transport documentation seem to suggest that all crossings must adhere to strict rules and regulations.......and I'm far from sure that these do.
.....
Apparrantly not, according to .gov response when somebody else questioned it.
Here you go Opti.

All pedestrian crossings are regulated by the Traffic Signs Regulations and General Directions 2016 (TSRGD). This includes zebras, puffins, and the type of pedestrian facilities at junctions referred to here.
TSRGD prescribes the signs, signals and markings that must be used to create the different types of crossing. The Traffic Signs Manual gives guidance on the use of road markings in Chapter 5, but the requirements of TSRGD take precedence over any good practice guidance.
In the Department’s view, coloured surfacing is not considered a traffic sign or road marking and therefore doesn’t come within the scope of the TSRGD. It has no legal meaning and therefore could be placed within the crossing studs at a signal-controlled crossing, or pedestrian facility at a junction.
The use of surfacing in this way needs careful thought.
Striped designs must be avoided – there is a trend to use surfacing materials (e.g. different types of stone paviour) in patterns to mark informal crossings, including some that are striped.
Our view is that any crossing that is not a zebra must not resemble one. That would extend to using a striped pattern at a signalled crossing. Zebra crossings have a defined priority in law, and anything that looks like one could lead pedestrians to assume priority when it doesn’t exist. The artwork must not alter the appearance of the prescribed crossing signals, signs and markings in any way, as this may mean they were no longer compliant with TSRGD.
It would appear that they may get away with it on traffic light controlled crossings with studs but not anywhere else, as some have been removed. A few wheel spin marks on them and the painting maintenance cost will soon piss them off.