i cant seem to find the textures for the dialogue and npc editor guis anywhere for a texture pack, im making an adventure map with this and it uses a texture pack to fit the theme of a mod that the map is being made with, but i cant make any changes to the gui, the dialogue gui being the main issue

im mainly wondering if it uses a vanilla texture that was left incomplete by the original pack creator, and if so what texture it uses so i can fix it

the dialogue gui:

the texture pack i clearly have on:

no texture to change with a pack?:

i found the texture, it was "demo_background" found in minecrafts gui textures folder for those who may come across the same issue