You will have fun on your journey with color(s). For your next project, plan a visit to the LQS. Lay the bolts out on the table. You will get a feel if they play nice together. Ask the clerks or other quilters as they are usually happy to help with selection.
If you have fabrics in a stash, take them out and play also. With practice, you will select the fabrics on your own and make great color combinations.