Changing Navigation Bar Texture

Hey all

I am using a Child Theme based on the Pinboard Theme and I have just changed my background to a red eggshell texture.

What I am wondering is this – is it possible to change the menu bar texture as well? It’s currently red with no texture but I woudl liek it to match if possible.,

Site link is https://www.ysgolycastell.org/pta

Thanks!