For the 1969 model year grilles there are two designs in the lower line cars, and "early" and a "late". The earlier ones are lighter and feature 3 colors. The later are darker and feature only 2 colors.  The Grande Parisienne in Canada (and Bonneville in the USA) received a different metal grille.

"First Jobs - Shadow Silver"
9795115 Right, 9795116 Left

"Later Jobs - Oxford Grey"
546147 Right, 546148 Left

I have absolutely nothing to support it, but assume the later ones were cheaper to produce since they required only one masking (extra color) whereas the early ones featured 3 colors and probably cost a little more to make. I've also heard it conjectured that the revised grill was an attempt to improve the front end looks, but I actually prefer the early ones myself! My 2+2 should have the laters based on its build date but I might end up with earlier ones because I have one NOS side already (pictured). That's my 2+2 original below which would have been salvageable but for the fog light bracket they poked through the mesh (you can see if you look...).