Kind of two answers in one, not sure which one fits better.
Red Green Blue, the primary colors.
Alternatively, you can interpret Red Green Blue as the three charges of the strong nuclear force.
We think you can see us everyday.
You don't even have to look closely.
You see colors around you everyday.
Alternatively, everything we see around us is made of particles held together by the strong nuclear force, though you would have to look very closely indeed to see particles that contain the individual charges themselves.
You cannot smell us, nor can you feel, hear or taste us.
Color cannot be smelt, felt, heard, or tasted, only seen.
Or, the strong nuclear force acts at such a small scale that humans cannot normally interact with it.
But we are somehow essential!
Because in the end, it comes down to us...
In the end, everything we see is composed of a combination of these colors.
Or, many of the particles that we normally interact with are composed of elementary particles with one of these charges.
... because without us, so many wouldn't even exist.
Not sure about this, without color we can't see anything but I guess objects can still exist.
Or, many of there particles we interact with everyday would not exist without the strong nuclear charges.
But to let so many exist, at least two of us have to form a team.
Most things contain a multitude of colors and at least two of the primary colors must be combined to create most of the colors we see.
Or, fermions(of which protons and neutrons are a part of) must have neutral charge so at least two charges(a color and an anti-color) must combine to create one, though most of the particles around us(portions and neutrons) are a combination of three charges.
And when we come together, beautiful can arise.
When the primary colors combine they can create many beautiful images.
The strong charges coming together are partially responsible for all the beauty in the universe.
Nevertheless, for some people... we and our childs are a hex.
In software development colors are often represented in hexadecimal.
Hex can also mean 6, if you count the anti-colors you can say there are actually 6 color charges.
But we hope that we can help those this way.