Yes - go for whatever you feel comfortable / good in, white/ pastels at any age . However, after a certain age I think a longer t-shirt /top is more flattering - unless you are one of the lucky ones whose derriere has not wandered south.
Just a caution re: pure linen trousers of any colour; they are high maintenance and , like all linen garments, really need washing/pressing after each wearing to look smart. Having said that, black ones tend to show the creases less obviously Not a problem if you have access to washing and ironing facilities on holiday and do not mind doing some laundry.
I always travel in darker trousers/ skirts and wear lighter colours after arrival as, inevitably, light colours are magnets for coffee, wine or food drips .
Enjoy your shopping and have a lovely holiday!