It is easy to mess up colour harmony by using formulas. For example, some premix a single (prevailing) colour into every colour on the palette. Worse yet is mixing that colour into white. However, true harmony requires different amounts of the prevailing colour for each and every mixture to be used, and there is no way to predict this. Take an early morning warm light versus the light later in the morning. Or a north light versus a south light on an overcast day.
To help you see these in life it is a good idea to mix colour charts. These little gems are done for each colour on your palette showing them in combination with each other colour in 5 values. Maybe a bit repetitive, but challenging and central to knowing your palette colours.