No, coloured 4D plates are not legal currently. It is crucial to ensure that the characters used on the 4D 3mm number plates are compliant to the DVLA guidelines in terms of size, font and spacing to maintain its legality. At RegLocker, all our products are compliant to the DVLA guidelines.
Both 3mm 4D number plates and 5mm number plates are legal and DVLA compliant. Hence, you have the choice to select the type of plate as per your personal preference and the desired aesthetics. The 4D 3mm number plates are sleek and have a refined look while the 5mm number plates have comparatively more 4D look than the 3mm ones.
No, as of now, DVLA does not endorse or issue 4D plates in the UK. Though DVLA has circulated guidelines and regulations that one must follow while customizing and purchasing number plates in terms of font, size and spacing. It is necessary to follow every regulation passed by DVLA.