Man Seeking Style Advice on Color Coordination

Message from G:

My biggest problem with dressing sharp is coloring – I do know how to dress classy,
But when it comes to colors other than white/black/blue solid colors, I get confused.
Which often makes me have a rather bland look.

The one issue that will help me the most is a color/pattern map – what works best with what.

When should a man purchase a pinstripe suit?

I generally like the look of a man in a pinstripe suit. I personally don’t own one yet but I find its properties attractive as I am around 1.7m ( 5 foot 7) and well-built. But could a man buy one as his second suit for instance? In other words, what occassions and what professions are appropriate for a pinstripe suit? Is it limited to people working in the banking sector?
Thank you in advance.