A couple of terms:
Tone: how light or dark a colour is
Shade: different shades of the same colour occur because of the variety of ways a colour can be mixed (i.e. some blues are mixed with a touch of red, while other 'shades' of blue are not).
Complimentary Colours: these are colours that are opposite each other on the colour wheel.
There are millions and zillions of colours!
We need only to open our eyes to confirm that yes, there are many colours out there! Within each colour of the rainbow, there are vast options for how that colour can be expressed. The shade of a colour is determined by the specific mixture of colours that create its colour composition. A yellow paint colour, for example, can be made by mixing cadmium yellow + a dash of burnt umbra + white. This will look much different than pure cadmium yellow.

