I know I’m a broken record, but this has become my go-to pattern for baby quilts. It looks great, goes together fast, and is a perfect size for a baby. As far as colors, red, white, and blue is always good, especially for boys. You could go monochromatic with blue or green, or you could pick a cute backing fabric and pull a couple of colors from it to make your top.
https://youtu.be/2-tA9yrJ9LE?si=eNk4P9R28nBBMV8G