Here's a nice vintage Sonic tie, that uses Sonic himself as the pattern! By making the classic stock art Sonics very small, and reducing the space between them, they become the (somewhat busy) pattern for the tie. The green background is a bit unusual, but it is not overly loud.…
Pajamas These are also available in the UK. The design is not painted on at all, rather it's dyed in there for sleeping comfort. There should be a Sonic on the pants somewhere, but Gear doesn't own this. Sizes are unknown.