Summarized from several sources, I've included links to more detailed descriptions of the religious symbolism of these five colors.
Red symbolizes the blood of Jesus Christ and the blood of martyrs.
[Crimson and Scarlet are associated with theology, the Church, and the Bible.]
Purple is the color of royalty (Jesus, King of Kings) and also the color of suffering.
Black represents darkness and sin and mourning.
White is purity and angels and resurrection.
Gold is a color of celebration and symbolizes the presence of God and richness (wealth, prosperity, or heavenly riches).