You Might be asking yourself "Why would I ever want to have my beautiful end cities look like the're made of prismarine?".
Well the answer is simple: Why not?
Also When I was throwing this retexture together instead of doing more important stuff, it didn't occur to me that we already have a block like the one I was making (aka prismarine), so here it is, a totally pointless retexture that makes end cities consistent with the end portal found in strongholds.

Note that some things and not finished like the chorus flower and chorus flower item textures that are still purple.

If you want the changes to end cities you'll have to manually install the datapack found inside the main resource pack folder.