Designers spend months studying color. The psychology of it. The value, saturation and intensity levels of color. The way colors look with and on other colors. Shades of grey. Color schemes - which are a lot more complex than most people know - are only a portion of what they study. They study it hands on, in depth and from every angle. Chances are that without taking a color theory class yourself you don't know what your designer knows about color - and a good reason to consult one when it comes to color schemes.
That being said....
there are some things you can do when choosing colors for yourself.
Buy a color wheel. Any store that sells art supplies generally will also sell color wheels. They are a basic tool. Some of them will have a color scheme "dial" on the back.
Know some basic terms: Hue: just another word for color. Red is a hue, Purple is a hue.
Tint: a hue with white mixed in. Pink is a tint. A pastel by contrast is a subdued version of the color - like mauve.
Shade: a hue with black mixed in like dark green.
Saturation is how pure the hue is - how much of the color is present and whether it has been dulled with grey.
Value is the lightness or darkness - how much black or white is mixed in. Fully saturated color always has a medium value.
And a bit of psychology...
Seeing red. Something sunny. There is a reason they call it the blues... In the pink! Green - more than just the color of ogres. Royal purple. Here's a clue - it isn't the new black. Neutral is more than black and white.
"Design is about living inside art. It's about art being livable and functional."
It has always been the focus of my life to "nest" and create a home. Not because I have some belief that only the woman in the home can do this, not because I think it's a woman's place. The reason I do this is the pleasure I get from the sensual input of textures and colors. The reason I do this has more to do with my reactions to my surroundings than about anything else.
My niece tells me, "You're always moving things around."
Yes, yes I am. Because a living space is alive and breaths and reacts to your life. So when I clean things get rearranged. Always.