I found a resource pack that have very cool and beautiful patterns and as the dev stated you can use those textures without permission
so we only need a recipe and adding textures
my idea for recipe is like terracotta and glass recipe but instead of using that first we combine a metal bar with a dye then we put the product of it to replace the terracotta in the middle of 8 glasses
here is resource pack's link : Better stained glass
Copyright notice(from dev): I don't mind you using these textures as part of your pack, you don't even have to ask me (although that's always appreciated). I do however request that you credit me as elwood612.