One of the most common BMW modifications is installing the 3 color stripes on the front kidney grill. The BMW M decal colors are light blue, dark blue and red. To be perfectly correct the dark blue stripe should actually be a dark violet but in most cases a dark blue stripe is used. The three stripes are part of the BMW ///M logo.
Installation is very simple. Press each one of the inserts into the grill. Stay away from the tape or stripes that stick on the grill. They come off easily and won't last.
Note that the stripes are curved more on the top than the bottom. Make sure to avoid installing them incorrectly.