Everything around you can be an inspiration in your creative products. Product advertisement in the papers, billboards, magazines will give you lots of ideas on the colours you can use.
Years ago, I bought 2 Color Harmony books. Color Harmony contains ideas on combinations of colors that you can use. At the back, there are color squares that you can cut out.
When I was making my ribbon roses clips, I will browse the book and look at the color combinations that I like and pick the satin ribbons with the nearest matching colors.
In Color Harmony, there are colour schemes such as Calm below, you can use the color combinations to invoke a calm feeling.
Even these books have been published a long time ago, the ideas in the books are still very usable today. You can see the application by designers on advertisement, clothing line, etc.