  Let $O$ be a differential graded (possibly colored) operad defined over
rationals. Let us assume that there exists a zig-zag of quasi-isomorphisms
connecting $O \otimes K$ to its cohomology, where $K$ is any field extension of
rationals. We show that for a large class of such dg operads, a formality
quasi-isomorphism for $O$ exists and can be constructed recursively. Every step
of our recursive procedure involves a solution of a finite dimensional linear
system and it requires no explicit knowledge about the zig-zag of
quasi-isomorphisms connecting $O \otimes K$ to its cohomology.
