I've not found any candle color that is specific to mothers, however, white candles are universal and are often used in place of another color when need be. Perhaps you too could use a white candle for your ritual. However, I've also provided a list of candle colors and their correspondences so that you may make your own decision on the matter. I do hope this helps you dear.
The following list was obtained from either "Wicca" or Living Wicca" by Scoot Cunningham. I can't quite remember which book it was, but I've read both and I believe they both have information on candle colors.
White: Protection, purification, peace, truth, and sincerity. (can also be used in place of another color, as it is a combination of all colors.)
Also, I know some of these colors may not apply to you and your desire, but I thought I would type up the entire list just in case you wish to use it later in spell work, rituals, etc.
One could never go wrong with a white candle. But a red candle means love, so maybe a red candle. Or maybe your mothers favorite color to honor her. I'm sorry for your loss.
I think I'll use pink, red, and lavender candles. Pink because in your list, Suliana, pink meant honor, red for love, and lavender because that was her favorite color. Thanks for the suggestions :)
Coloured candles used in the Craft are rather modern. Of course, if they aid you in your work,that is fair enough. But I have never used other than white candles. Many years ago when I asked my teacher why we had candles on the altar she told me that it was partly tradition, and that it was the flame that mattered,not the candle. She said that in old times, before gas and electricity,candles were merely a form of lighting; but they do,in a small way, represent fire.(The Sun).
How is your mother? her personality her interest and her favorite colour. I would say Pink off the Bat but think of what Aura she always give off maybe get a colour that is not the same but would Compliment it. Love the Candle idea btw.