It's correct that the colours we perceive are dependent on the frequency of light. That frequency is the rate of oscillation, around 100 million million oscillations per second. That's a different thing than the speed at which light travels, about 300 million metres per second.
It's a bit subtle, though: humans (most of them) have three colour receptors, pigments in certain cells in the retina, at the back of the eye. All we can 'see' is the recipe for how much each receptor is stimulated, the ratio of signals R:G:B from our red, green and blue receptors. These are sometimes called 'additive' primary colours.
So when we see 'yellow', it can be a single frequency of pure light that excites some red and some green reception in our eyes. Or it can be light not at the single yellow frequency, but red light and also green light from two sources -- either will cause the same stimulation in our eyes, and the brain will 'read' the same signals.
So, for colour television, we don't need all the colours of the rainbow, teased out by a prism from white light: red, green and blue phosphors (or LEDs or lasers) are enough to simulate what we can see.
Inkjet printers use 'subtractive primary' colours: cyan, magenta and yellow. Yellow can be made up of red and green light,, no blue, so yellow ink absorbs -- or subtracts -- blue light. Magenta is red and blue, not green (white subtract green), and cyan is blue and green, not red (white subtract red). So inks, like paint, compose their colours by figuring out what does NOT belong. Just as the answer about the colour of a orange fruit, the 'inks' (pigments) in the fruit soak up all the colours in white light that are NOT orange.
Try this: shine a bright light on an orange, and a piece of white paper near to it, and shadowed from the light. You'll see the colour of the light that comes off the orange...