This answer probably will not answer your question, because you have not a specific question, but it is meant to be a guideline for you to investigate further.
I would like to have a better understand of colours theory
I am not sure if you have the concepts right.
- Color science (Light, physiology...)
- Color theory
- Color psychology
- Corporative design guidelines
- Color trends
- and there is good taste
very bad logo colours
This is the first thing you need to analyze. Why they are bad? What could be a better option? Can you modify a bit the tone, or the hue or saturation, to make them better? Are there already some corporative guidelines?
Is the "bad logo color" an intrinsic relationship problem? Is it just a matter of taste? Does it has a contrast problem?
I can go on and on... You need to have a methodology to analyze problems and then you will have solutions at your fingertips.