What value is
Value is how light or dark a color is, separate from its hue. A navy and a forest green can be nearly the same value, and in a quilt they will read as one fabric.
Patterns are built from contrast in value. The star shows up because its points are darker or lighter than the background, not because they are a different color.
The black-and-white test
Stack your fabrics, take a photo, and switch it to black and white. You are looking for clear steps from light to dark.
If two fabrics turn into the same gray, they will blur together wherever they touch.
What to swap
Keep the fabric you love and swap its neighbor for something noticeably lighter or darker. Usually one change fixes the whole quilt.
Save the close values for places that should blend, like a background made from several creams.
See it on the grid
Color your layout in the Quilt Builder before you cut. If the pattern disappears on screen, it will disappear in fabric too.