Color the grid and reveal an image. At the top of each column, and at the side of each row, you will notice a set of one or more numbers. These numbers tell you the runs of colored squares in that row/column. So, if you see '4 1', that tells you that there will be a run of exactly 4 squares in the indicatd color followed by a single colored square. If the 4 and 1 have the same color then at least 1 white square is between them.