Can you tell me Which WordPress Theme is this Site http://www.blankcanvas.studio is Using
Why not look at the source code and see for yourself?
It's not hidden at all...
It is give me theme url where i can buy it
As the name of the theme matches the name of the site, I'd say the chances are very high that it's their own custom theme and you can't buy it anywhere. An Internet search should confirm or refute that theory.
That theme can be created very easily.