use background as lookup instead of base_name

colors/neobones.lua

@@ -3,7 +3,5 @@ vim.g.colors_name = "neobones"
 package.loaded["neobones"] = nil
 require "lush"(require "neobones")
 
-local util = require "zenbones.util"
-local base_name = util.bg_to_base_name()
-local p = require("neobones.palette")[base_name]
+local p = require("neobones.palette")[vim.opt.background:get()]
 require("zenbones.term").apply_colors(p)