I’ve been taking pics of the groupings of objects in front of shrines.
Here’s what they may mean:
A candle or an oil lamp: the light of wisdom illuminating the darkness of ignorance
Incense: the fragrant scent of morality
Flowers: the aspiration to achieve the body of the Buddha, or, alternately, a Zen verse expresses the desire for the mind’s “flowers” to “bloom in the springtime of enlightenment”
Food, water, drink: represents the nectar of Dharma and the wish to achieve it
Scarves: offering friendship
That’s the simplified form, ripped from here
I’m presuming the pigments are an extension of the forehead markings. These pics are from Hindu shrines, so they may mean this but that’s only a guess. (I need a day with a guide, but Googling has its benefits, like you can drink beer and smoke ciggies and do it)
Why a stone? A cool answer here