True History of Candle use in Magic

Colored candles can be excellent magical tools, however, candle magic
in its current form is a relatively modern addition to Witchcraft
spellweaving.

Colored candles as we know them today have only been common for the
past 30 years. Prior to this, most candles available were of the
utilitarian white variety. The dyes used to color wax must be oil
soluble and are therefore only available from limited sources:

1) Plant based colorants were rare until recently, and were only
capable of coloring wax to the warmer hues of the spectrum. (Red,
orange & yellow) They generally cannot create green, blue or purple.
This, at least shows us that no Witches in the middle ages were using
purple candles to increase their psychic perceptions or blue ones to
highten the spiritual and protective energies of their homes.

2) Pigment dyes were another limited source of colorant. They are
extremely finely ground minerals, so finely ground that it was not
possible with the technology that preceeded the early 19th century to
utilize them as colorants. For example: Although copper carbonate was
available, the ability to grind it finely enough to remain suspended
in wax as a (blue-green) colorant was impossible before the early
1800's.

3) Aniline dyes were obviously not available until quite recently.
Derived from coal and oil, they have only been available since the
late 19th century.

Before the 16th century, candles were made of animal fat (tallow) or
sometimes 'lamps' containing oil with a fibre of some sort as a wick.
They often smoked, sputtered and smelled. Only the elite (which it is
unlikely the village Witch was generally a part of) could afford the
more rare and costly beeswax candles. (Harvesting beeswax sacrifices
a great deal of honey production, therefore it is unlikely that
they 'made their own') Stearin, the chemical compound that most
modern candles are made of was originally produced in the early 19th
century, and candles in general have only become widely available
since the 1960's.

So what is all this getting to you ask? What is the point? Well, if
you pick up a book that claims Egyptians used lapis blue colored
tapered candles to contact spirits and the Celts used silver and gold
votive candles to represent the Goddess and God, put it down. Books
filled with this type of misinformation are out there! They may
contain original and creative ideas for the use of candles and
colors, but if they claim that these are "ancient" or
even "traditional" Witchcraft techniques, they are most likely fakes.

http://www.whitedragon.org.uk/articles/candles.htm