Just to make sure: you’re putting the color tiles over the black-and-white picture? There was a player before who was trying yo rearrange them next to the greyscale image, which is not what you need to do. So just drag and drop the color tiles on top of the appropriate part of the greyscale.
I am moving the tiles to the grayscale image. The problem is that there are alot of tiles to drag and drop in the time limit for success. Especially on an Android. Maybe either less tiles for the first assignment or a longer time limit for success would be better? After all, this is the first illumination assignment.