Indigo or Navy Design for a House

This page is the CodyCross answer for the clue below from Greece, Group 673, Puzzle 3 (Feta Cheese).

Question is: Indigo or Navy Design for a House

and the answer is: BLUEPRINT

Word Meaning:

BLUEPRINT — A type of paper-based reproduction process producing white-on-blue images by means of a photosensitive ferric compound, used primarily for technical and architecture's drawings, now largely replaced by other technologies.

Definitions from Wiktionary.

Indigo or navy design for a house — CodyCross Answer | CodyCross Solutions