A Painting On A Canvass

Like in a painting, but only sketched in blue, the sky is laid upon a seemingly dark canvass. The length of the canvass is actually a matter of debate. And also the shape. If it's limitless in length, it's not round in shape. If it's round in shape, it's not limitless in length. But the canvass is not always dark. When the sky is blue, it's very palpable to assume it to be dark. And when the sky is dark, the canvass must be colorless. The latter color is not very palpable. Because, it won't be too alien to consider that the dark sky does not portray any color at all. Instead, it can very well be that the dark sky is actually showing the canvass directly. In that case, the canvass must be a painting itself. So is the artist mad? Why would the artist paint upon an already painted canvass? And why does the canvass has to be a painting itself? A dark painting? Maybe the artist does not have an option. He has just got only one canvass to work on. Or...there might not be any artist at all. The canvass, might just be a canvass. And not at all a painting. It maybe that the canvass is like those things which changes its appearance, depending on the angle in which light falls on it. Yeah, that kinda solves the riddle. A canvass with two faces, both on the one side. Or...maybe there is indeed a canvass, upon which two paintings are done - one dark, one blue. And the paintings have been done in the same way as are those color-changing things. But then, what's the color of that canvass? Damn it. The riddle is not solved yet. More thought must be dipped into the pool of thinking. A lot more than as previously thought would be necessary.