[dread78645]

If they're the same thing how come I can see one, but not the other?

Because your eyes are sensitive to wavelengths between 700nm-450nm.

At any rate, I think you are saying every wave within the electromagnetic spectrum travels at the speed of light. Yes?

Yes. Up to the point where the refractive index of the transmission medium becomes a factor.
At the frequencies we're talking about, air @20°C has a refractive index of 1.00029 or about 0.03% slower than it's speed in a vacuum (index=1.0).
For completeness:

lf = c/n

Where:
l - the wavelength
f - the frequency
c - the speed of light
n - refractive index

Since n is essentially equal to 1 ...

lf = c/1 or lf = c.

[Fester Chugabrew]

Thank you.

Has the entire electromagnetic spectrum been discovered and explored by science? Why is it necessary to assume "nothing is faster than the speed of light in a vaccuum?"