If you click and hover over the paint it will show the name of the paint at the end of the address. If it's a world made by someone who used different paints (downloaded/made), you won't have them in your game files. You'll have to download them or extract them from the world with S3pe to get them in you CAW files Just to show a thumbnail.
This is one of my worlds but I've rearranged my textures since I've updated the world so the thumbnails are not in the same spot. This shows how clicking/hovering on the texture will show the name of it at the end. :)
https://i.imgur.com/2SVqPkS.jpg