Sorry, but I do not know English. I hope I can help you anyway.
From the Main menu, select OPTIONS and then COLORS.
Choose Bud - Western and adjust the black color for T - shirts, trousers, shoes and belt.
Then choose Terence - Western and adjust the black color for T - shirts, trousers, shoes and belt and item.The black color is always the first on the third row as shown in the picture.
Once everything is set, go back to the main menu and start the Old West level
Achievement is immediately unlocked.