These letters can be printed in a multitude of colors from the iconic green-white-red to a more simplistic all white. Switching colors during printing is required to obtain color difference.
Letter mounts are placed on the back of the grille, the letters on front. M5 bolts or screws can directly be screwed into the printed part, in one of many mounting holes, such that it's always fitting. Around three screws for each letter should be fine. The letter A should be printed twice.
No particular print settings required, no support needed.
The author marked this model as their own original creation.