Certainly
White or the color dress of the bride
The general etiquette for the mother of the groom is to wear an elegant dress in a neutral color, such as beige or gray, so as not to outshine the mother of the bride (regardless of the color of the mother of the bride's dress).
The mother of the groom should ask the bride's mother what color she will be wearing. Or ask the bride what colors will be used for her bridemaids. There are only two colors she shouldn't wear - white or black. White, because only the bride should wear white. Black because it means mourning and women shouldn't be wearing black for a happy ocaision. Most mother wear blue. Although in these modern times of looser protocols, the mother of the bride and groom can choose to wear black if the color theme of the wedding is black/white. Ivory, cream, off white could then be considered the "white" colors to wear without necessarily wearing white.
Why not!
I don't think so.
If you like you could wear a carnation in your mother's favorite color.
No, it is not traditional for the mother of the bride to buy a nightgown and pajamas for the bride and groom. Sometimes the groom may wear just his underwear; just wear pajama bottoms or even be in the buff. The bride should pick out a nice negligee for her wedding night.
they wear pinks, even yellow and orange is acceptable
A mother of the bride looks best in a color that is complementary to the bride's dress. In doing this, she matches the overall theme and tenor of the wedding itself. A good rule of thumb is to select a color that may be similar to the color of the bridesmaids' dresses. For example, if the bridesmaids' dresses are lavender, a mother of the bride could select an outfit in plum, lilac or light blue. Another good rule of thumb is to select something in a neutral color, such as taupe, brown or navy. It is preferable that the mother-of-the-groom and the mother-of-the-bride should not be in the same color, but rather in colors which coordinate.
you wear black
The mother of the bride is definitely defying tradition by wearing black but this is the 21st century and there are lots of black/white theme weddings. The mother of the groom could wear the traditional beige or champagne to coordinate with the mother's choice of color. I am not sure what "candy apple" means. Is that green? If so, then she could choose a color more in line with the bridesmaids' dresses and wear lime, jade, hunter green or sage. If it candy apple is red, then the MOG could choose red, burgundy, wine, cinnamon.
red