Shueisha, Spy × Family‘s publishing company, decided to celebrate the manga’s success by offering a full colour edition available exclusively online. It comes with an unusual choice of colours that gives the work a retro effect. 
Title: Spy × Family (SPY×FAMILY カラー版)
Author: Endo Tatsuya (遠藤 達哉)
Language: Japanese (raws)
Source: purchased by me
Volumes: 1-5 (of 8?)
Volume 1 
Download »77.69 MB
Volume 2 Download »71.15 MB
Volume 3 Download »71.65 MB
Volume 4 Download »12.83 MB
Volume 5 Download »82.12 MB
The original manga series is serialized in the online magazine Shounen Jump+. Description (from Wikipedia):
The story follows a spy who has to “build a family” to execute a mission, not realizing that the girl he adopts as a daughter and the woman he agrees to be in a fake marriage with are a mind reader and an assassin, respectively.