All shades of a colour will have the same properties of that colour (eg light blue, royal blue, navy blue all have the same properties as "blue")

Black- returning to sender, divination, , protection, banishing negativity, evil, loss, discord, confusion, negativity, remove hexes, contact spirits, truth, reversing, uncrossing, releasing.
Blue/black- wounded pride, broken bones, angelic protection.
Purple- calling up the powers of the ancient ones, sigils/runes, government, spirituality, Tension, ambition, business progress, power, healing, power, spiritual development, intuition, spiritual communication, protection, legal matters, progress, breaking bad luck, negativity, banishing evil, stop gossip & lies, material wealth, astral travel.
Lavender- to invoke righteous spirit within yourself, favours for people, spiritual development, psychic growth, divination, sensitivity to the other world, blessings.
Dark Green - regeneration, agriculture, financial.
Mint Green - financial gains. (Used with Gold or Silver)
Green - healing or health, money, finance, fertility, luck, growth, employment, nature, harmony, equilibrium, emotion, intuition, instinct, fortune, balance, prosperity, courage, agriculture, changing direction or attitudes, attraction, children, faery magick, understanding.
Avocado green - beginnings.
Light green - improve weather.
indigo blue - protection on the astral levels, defences.
Dark blue - create confusion, ( must be used with white or you will confuse yourself), Impulsiveness, depression, changeability, change, psychism, water, truth, dreams, Goddess, protection, change, meditation, impulse.
Blue– protection, love, sincerity, loyalty, wisdom, justice, organisation, healing, meditation, tranquillity, equilibrium, peace, patience, communication, honour, health, friendships, dreams, sleep, inspiration,  harmony.
Royal blue - power, protection.
Pale/light blue - protection of home, buildings, young males, peace, wisdom, integrity, Tranquillity, understanding, patience, health, happiness, psychic awareness, intuition, opportunity, understanding, quests, journeys, depression.
Ruby red - love or anger of a passionate nature.
Red- love, romantic atmosphere, energy, passion, creativity, Strength, health, Vigour, sexual love, protection, courage, enthusiasm, fire, power, sexuality, will, stimulation, lust, destroying, change, transformation, loyalty.
Light red - deep affection of a non sexual nature.
Deep pink - harmony, friendship in the home.
Pink- harmony, friendship with people, binding magic, honour, love, morality, beauty, partnerships of all kinds, romance, attraction, inner harmony, calming, relaxing.
Pale pink - friendship, young females.
Greenish yellow - Sickness, cowardice, anger, jealousy, discord.
Yellow– healing, intellect, attraction, persuasion, charm, confidence, study, divination, activity, creativity, sun, clairvoyance, learning, the mind, mental alertness, prosperity, change, harmony, knowledge, understanding, movement, astral projection, telepathy, contact spirits, protection, Wishes, concentration.
Amber– Develop Witchery skills.
Deep gold - prosperity, sun magic.
Gold- healing, intellect, attraction, persuasion, charm, confidence, study, divination, activity, creativity, prosperity, power, physical strength, Success, achievement, Mental growth, Skill, Intuition, fortune, understanding, knowledge, emotions, harmony, hopes, fortune, money, healing.
Pale gold - prosperity in health.
Burnt orange - opportunity.
Orange- material gain, attraction, work, career, encouragement, adaptability, healing, stimulation, attraction, energy, intellect, leadership, communication, travel, strength, authority, luck, vitality, dominance, control emotions, creativity, memory, career, legal matters, balance, neutrality, organisation, writing, business transactions, information, cooperation, quick change.
Dark brown - invoking Earth for benefits.
Brown- peace in the home, herb magic, friendship, hesitation, uncertainty, neutrality, healing animals, concentration, absorption of knowledge, intuitive communication, earth, house, physical objects, endurance, steadiness, uncertainties, centring, grounding, material gain, building, study, concentration, finding spells.
Pale brown - material benefit in the home.
Silver- quick money, gambling, invocation of the moon, moon magic, psychism, cancellation, neutrality, stalemate, meditation, Success, balance, negativity, clairvoyance, divination, astral travel, energy, inspiration, protection.
Off white - peace of mind.
Lily white - mother candle. (burned for 30 mins at each moon phase)
White- righteousness, purity, devotional magic, truth, sincerity, protection, peace, purification, innocence, children, justice, doubts, fears, meditation, divination, spirituality, increase psychic powers, healing.
Gray– glamouries, cancellation, hesitation, neutrality, balance, attuning with the spirit realm, peace, patience, veiling and invisibility, vision quests, theft, decision making.
 

White contains all the colours in the spectrum, so if you cannot find a candle of the right colour, you can always substitute white for any colour.
 

More information about spellcasting can be found in  "Obsidian's Book Of Shadows", from Obsidian's SpellCasting booklet or from Obsidian's Classes.  Available from:.