If it's an important large work on expensive media, and if your printer will co-operate, use a non absorbent media such as a thin sheet of clear flexible film, and print the appropriate part of the image on it. When it comes out the ink won't have soaked away and will be the exact colors missing from the large image. Use a small paint brush to fill in the missing bits.
Some experimentation might be required to get some wet ink that isn't so much that it mixes freely with adjacent color, or make sure you
only print the one color at a time.