There are 7 Principles of Design that you can use in designing your garment:
📌Balance
📌Proportion
📌Emphasis
📌Unity
📌Repetition
📌Rhythm
📌Variety
Also, there are 5 Color Schemes to guide you in choosing the perfect color together:
📌Monochromatic Colors Scheme
📌Analogous Color Scheme
📌Complementary Color Scheme
📌Split Complementary Color Scheme
📌Triad Color Scheme