See tips for getting a transparent look in your quilts from designer Rebecca Silbaugh as seen in her Color Cubes quilt from the American Patchwork & Quilting August 2015 issue. Buy the pattern here.

To get the look of transparency, break down the process of choosing fabrics into a few steps. First, ignore the areas that seem to be overlapping and choose fabrics for the five 'squares' and the four 'rectangles' in the block. Then choose a fabric for each point where one of the squares and rectangles seem to overlap by imagining what a mixture of the two fabrics would look like, thinking about both color and value (lightness or darkness).

See the pictures to get ideas of how to use various colorways in this block design.