@Monique ah this is similar to what we have atm!
I think these ones are really pigmented and the colour comes out really well!
https://amzn.eu/d/9sYEm2L
https://amzn.eu/d/1eNQApZ
https://amzn.eu/d/bFbGwo2
Ali suggested what I was going too. I second all 3 options, also the crayola washable colours
Thanks guys!!
We have felt tips that are washable but i prefer these, they're really good - https://amzn.eu/d/198Ik9m