Are these number plates legal?

Yes: they are fully legal with all compliant road regulations, Spacing, Font and legal markings.

How long does shipping take?

Normally from the date of purchase its 2-3 working days

The design and appearance of number plates?

There are often regulations governing the design and appearance of number plates, including size, font style, and color. These regulations are typically enforced to ensure visibility and readability. Check Gov site for more specific details.