The way these worksheets work is that there are addition problems in each square. All of the addition facts have a sum of 10 but they use different facts to make 10. So some of the squares have 9 + 1 while others have 8 + 2, and so forth. Each different fact uses a different color, so all of the 9 + 1's are colored blue while all of the 8 + 2's are colored green.
Also in other news you can now purchase items from my store directly on Facebook. Here's a link to the Facebook store so go check it out.