You didn't say how big your blocks are. I made a big assumption, possibly wrong, that the center square corresponds to the 5" charm, which would mean your blocks are 7". It may be that you intend to cut down the center square... but if not, then I think you will need much more fabric. If the center square in the square is 5" finished, then the block is about 7" finished, or 7.5" unfinished.
Of the light brown you will need eight 7.5" squares in each of the 15 rows, for a total of 8*15=120 squares. With standard width fabric (I usually count on 40" usable) you can only get 5 squares in the WOF, so you will need 120/5=24 strips. 24*7.5"=180", which is 5 yards. You will need to buy more than 5 yards to account for squaring up and shrinkage if you pre-wash. With your design, you actually have more
You also have 120 diamond-in-square blocks. For each one, you need two squares cut at *about* 4.5", and you will cut them on the diagonal to make the block. (You may use another method; this is the most conservative, fabric-wise.) That means you need 240 squares, and you can get about 8 in each WOF strip. That means you need 30 strips, each at 4.5", or 135", = 3.75 yards. This doesn't include anything for the border!