I bet that's ^^ the title of a book somewhere.
Here is how I use color in my lineart and shading to make my art more POP off the page.
This elf's skin is lined with a deep red-orange instead of black, so soften the look of her skin. I also make the sheer fabric lines of a dark green to enhance the idea that it is transparent and of a different material than her robe.
Adding color to your lineart softens the look of you art on the eyes- people in real-life don't have black outlines! But I rarely do it in the beginning- instead I lock the lineart layer-- doing so makes it so that my tool can ONLY draw on top of what's already drawn in that layer-- and then I quickly brush over the black lines with a new color.
Another example, Top all black lines on the character, Bottom softend with colors on the hair, skin, facial features:
The secret to vibrant art is complementary colors- or even more basically COLOR for your shadows, not just making the same color more black. Complementary contrast your base colors perfectly, making them appear brighter!
Here are some pages of the color theory pamphlet I made for my younger sister Jenessa!
The colors were done with Tombow markers, which blend differently than alcoholic markers, so I didn't get quite the look I wanted for the cloaks.
Shading: Don't use black.
Shading with black vs shading with complementary colors
Though black shading/ or shading with gray gradient is a staple of American superhero comics, I find complementary colors more natural.
Complementary vs analogous on skin
The orange on the light beige makes for warm lighting while the lilac on top of the beige creates true shadows, a little mysterious with that harsh light portrayed by the sharp lines.