I started playing around with Imagemagick. I took an image and added a slight red tint to it:
convert -fill 'rgb(100, 0, 0)' -colorize 20% DC_eyes.png DC_colored.png
I then decided to composite it over another image:
composite -gravity center DC_eyes.png midastouch_1280x800.jpg midastouch_1280x800.jpg
The foreground was a bit too small though, so I had to scale down the background:
convert -resize 1152x648 -quality 100 midastouch_1280x800.jpg background.png
Then I composited the two images again:
composite -gravity center DC_colored.png background.png background.png