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.
the mother of the bride should wear red because it color coordinates well.
If the bridesmaids dresses are colours like regency, violet or blue I would say a Teal dress. Teal compliments silver extremely well.
Only if the bride wants her there.
The critical thing is that she shouldn't take attention away from the bride. Everything else is largely irrelevant (though ideally she should neither wear the exact same color as the bridesmaids nor something that clashes hideously with it).It's pretty common for there to be at least a few photos of the wedding party and the family together (it's also fairly likely that at least some of the bridesmaids will be family, and therefore in the family photo even if there isn't specifically one of the family with all the bridesmaids), and you don't want the mother to be mistaken for a bridesmaid, or for the colors to clash too much.
There is no limit at all to the amount of bridesmaids you can have.
* Unless the bride so chooses to do so then no, the groom's mother does not get a gift. Both mothers should have corsages at the wedding.
The mother of the bride must wear a bright coloured dress or suit to show happiness and is also a sign of good luck for a happy marriage
It should be Bridesmaids' because since bridesmaids already ends with an s all you have to do is make it possessive by adding an apostrophe after the s.
a white dress and white shoes with a red bow around the 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.
seaweed green
Since it is the bride's mother who is sending out the invitations, which is customary then the return address should be to your parents or your mother.