Update ex_004.md

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docs/ex_004.md

@@ -27,7 +27,7 @@ The 'multiple of 16' rule is perhaps the most confusing here. VERA stores palett
 The code and makefile for this example can be found in the [tile_wall sample](../samples/tile_wall), and we'll rush through the Aloevera commands here as there should be nothing new. The Palette can be imported directly from the image data, and the only difference is that we're going to set the tile width/heights to 16 x 16 and we'll format the Imageset to 4BPP, since we have fewer than 16 colours in the palette:
 
 ```.sh
-aloevera -p project.av palette import tile_w all_pal tile_wall-imageset-4bpp.png
+aloevera -p project.av palette import tile_wall_pal tile_wall-imageset-4bpp.png
 aloevera -p project.av imageset import wall_tiles 16 16 tile_wall-imageset-4bpp.png
 aloevera -p project.av imageset format wall_tiles tile_wall_pal 4
 ```