I agree. I also like to add that at times, I use red candles to improve one's health. It won't heal the person and doctor visits are still recommended, but due to my poor health, meditation and spell casting using red candles has help me improve in some ways, health wise. I usually use pink candles when healing the broke heart or for love. I have not tried substituting it with red candles. I'll consider it.
The above answers are right, but, if there is a certain color that means something to you and it is associated with a different meaning, go ahead and use it for what you want, for example: Red is used for love, if you see it as a use for peace go ahead and use it for peace. It is about intent that matters. I personally follow what the colors are associated with, but it is not required.