Using global textures you can cut down on the repetition of textures without creating several nodes.​ This method works on all solid nodes, and should work on most nodeboxes, though things may get a little janky on some. I've included some sample code here so you can just copy and paste the code, and modify it to fit your needs.

minetest.register_node("global:grid", {
   description = "Color Grid",
   tiles = {{name='global_grid.png', align_style='world', scale=4}},
   inventory_image = '[inventorycube{global_grid.png&[sheet:4x4:1,1{global_grid.png&[sheet:4x4:1,1{global_grid.png&[sheet:4x4:1,1',
   groups = {oddly_breakable_by_hand=3},
})

minetest.override_item('default:brick', {
   tiles = {{name='global_brick.png', align_style='world', scale=4}},
   inventory_image = '[inventorycube{global_brick.png&[sheet:4x4:1,1{global_brick.png&[sheet:4x4:1,1{global_brick.png&[sheet:4x4:1,1',
})