Blocks of Cells and Color Fill

Hey folks! Long time browser, first time poster.

Ok. I have a spreadsheet with almost 5000 lines of data. I need a macro that will separate blocks of 100 lines at a time, each block of 100 filled with a different color. Maybe 3 or 4 colors will work.

To make it even more difficult, I also want to check macro to make sure the Data in column i after the 100th cell doesn't match the previous cell. If it does, then to color that cell as well.

Attached is a sample of what i would like it to look like. You will see line 101 matches 100 so it is colored the same as the first 100. Line 301 and 302 match the previous cell, so it selected them.

Any help you can provide would be great.