Good morning star. Welcome to Eribafolk and congratulations on your new purchase.

Curtains:-
We think you'll probably find it very difficult to source ready made curtains for an Eriba, especially in bright colours. They normally come in 3 shades of drab.
Many owners who wish to brighten up their vans usually pick a lively colour fabric and either make them themselves or get somebody locally to run them up for them. They are very easy to make (evidently )
Owners often keep the original curtains to put back into the Eriba if they sell it. The biggest problem is sourcing new curtain hooks but there is a huge selection on Ebay or you could "borrow" the hooks from your existing curtains.
R and A