RED & Black threads
The use of colours in Magick varies from group to group and from culture to culture. Red and black are often associated to magick due to the misconception involving the existence of "black magick" and "white magick" which has been spread for too long. Also, black is connected with "darkness" and red with "blood" as it's said that some self called "satanists" perform some of their rituals using blood.
There is no such a thing called "black magick" nor is "white magick". There is only Magick. What people do and how and why they do it is a different thing.
This is only one of too many misconceptions about Magick and who practise it.
Black is associated with Saturnian energy and with number 6. It is used in uncrossing and unbinding rituals, defensive spells, for protection, to induce a deep meditative state, to banish negativity, etc. And as it absorbs, it's worn in funerals, to release depression and remove confusion, pain, etc. It can be used with red to increase the power of intent in rituals.
Red is used for energy, vitality, passion, sexuality, lust, anger, victory, agression, courage, fear, strength, and to attract luck. Associated with Mars and the number 5, it should be used with some caution as it's energies can be unpredictable and chaotic.
These are a few things linked to the use of red and black colours in magick.
The red string worn around the wrist is a good example of the symbolism used in Magick. The Kabbalah followers wear that string around their wrists. It's said that the ancient witches used to go to the tomb of Rachel (a matriarch of Israel in biblic times, one of the wives of Jacob, mother of Joseph and Benjamin, whose love for children was well known) taking a long red string, which they wrapped around her tomb several times to charge it with the maternal, protective energies.
The string was then cut into pieces and worn around the left wrist, as the left hand is receptive, so that they received the gift of her protection against the Evil Eye.Linkback: https://www.astrogle.com/forums/occult-magick/11/red-black-threads/31/