If no colors are locked Colormind will generate color palettes at random.
If you have a specific starting color in mind, pick that color and lock it. The location of the color does matter, so experiment with different placements.
If you have two complementary colors, try placing them at the opposite ends of the palette. Colormind will tend to generate nice intermediate values.
If you want more variety try placing contrasting colors closer together, colormind will then tend to create triadic and other more complex color schemes.