You will cut your fabrics as follows:

each light fabric – cut one 3 inch strips the width of fabric  (I used 2 strips to make larger)

each dark fabric – cut two 2.5 inch strips the width of fabric (I used 4 strips but you need a smidge over 1/4 yard)

each medium fabric – cut two 2.5 in strips the width of fabric (I used 4 also but again you need a smidge over 1/4 yard)

Here is a picture of my cut strips using the light, medium and dark purple.  You can cut the strips in half if you prefer to work with shorter lengths.  I found it just made life easier.