Look into colour psychology, it’s an established area of study, and can lend its weight to magickal workings. Although do take into consideration that different cultures have different meanings for colour – e.g. in the West you wear black to a funeral, but in many Eastern cultures white is the colour of mourning. Or the West has brides wear white at a wedding, but in the East the bride wears red.
In general, colour psychology will be your best bet.
Spirits and planetary energies has color correspondence too. If your petition is for a specific spirit find their color preferences and make a colorscheme based on that and the colors that fits the petition. You can create a painting with that!
Ironically it was Queen Victoria who started both trends. Before her brides often did wear red and mourners either wore what they had or sometimes white(rare because it would get dirty too easy in those days before dry cleaners snd washing machines). It’s actually fascinating how so many things we think of as normal and tradition actually only started with Queen Victoria (white bride dresses, Christmas trees etc).
Add: books on color psychology are also interesting.
In general, yes color has power. When creating sigils or spells the additional color correspondences can be powerful. That’s also why some spells call for certain color candies etc. That’s not to say magic won’t work if you don’t use a specific color, but layering is important to witchcraft, given you know your limitations as well. As mentioned before, correspondences like this depend on your own culture as well.
It sounds trivial but I enjoy using Magic: the Gathering’s “color pie” as a good idea for what colors can represent, as well as other fantasy medias (growing up playing rpg games I’ve associated green with wind more than nature, and in my culture black represents earth anyway).
You have the power to control the color representation but it’s also not just what you want it to be, it’s what you internalized and feel it to be given whatever society or culture you thus live/d in.
In planetary magic each planet is given a color or set of colors that represent them so that you can create planetary sigils in the proper colors while also working in the special hour, and for some wearing robes of those colors draws the energy as well.
I’ve actually mentioned all this in a beginners post I made, perhaps you can find it useful: