Start with one garment. You get the colours that work with it, the shoes, and the reasons, so you can judge what you already own.
Navy tailored trousers: a supporting piece, so it needs a clear relationship with whatever anchors the outfit.
Colours here are typical dyed-cloth values, not reference swatches, so navy is the greyed navy of a real suit. Your own garment will differ, and so will the same colour in a different fabric.
The list is ordered by how comfortably each colour sits with your garment and how much contrast it gives. The top of the list is the easiest choice, not the only good one. A lower result with a clear reason can suit you better, and the notes say what to watch for.