Prayer Candles? are there any requirements?

[morbe]

Hello everyone, I wanted to start making my own prayer (offering) candles for my self and friends to light and use at home and to light at chruch and where they can.
I know that the Catholic Church can be very strict and traditional. I have searched the internet far and wide and still can not find if there are any regulations or requirements to making and using a home made prayer (offering) candles. Ive seen various sizes and colors.
But is there a requirement on what type of wax or wax mixture?
Color vs Plain White?
Size in weight or shape?
Thanks, everyone

 

[pianistclare]

Our parish uses only beeswax candles, of the tall 7 day off-white variety. They come in tall plastic inserts for the permanent glass holders in a stand.
Most parishes (around here anyway) buy them in bulk from one of 2 or 3 major suppliers.
We don’t happen to use the small votives in our parish.