So many teachers and books insist that people buy the colours they themselves have grown to like. Everybody has different taste and you can safely rely on the likelihood that your preferences will change as you walk your path.
The fundamentals are these: There are three primary colours, from which all other colours can be made, however, there are no pure primary colour pigments so the statement is theoretical.
We recommend beginners start with a “warm” (tending towards red on the colour spectrum) and a “cool” (toward blue) of each of the primary colours (eg. a lemon-yellow and a golden-yellow, a scarlet and a crimson for the reds, and a cerulean and an ultramarine for the blues). This will simplify your colour mixing enormously.
Note that each manufacturer labels their colours slightly differently. Most use names that signify some property of the pigment or colour eg a cadmium red of a particular brand should be close to the cadmium red of another brand. Some colours and names are unique to some brands (eg. Australian red-gold of Art Spectrum) We recommend you also begin with some earth colours (burnt sienna, yellow ochre and raw umber) to save time making these ‘combination-colours’ from scratch; and because they’re used so liberally for most types of painting.
Of course a white is important. Whites are either very opaque like titanium whites, or less opaque (semi opaque), like zinc or flake (lead) white. The more opaque, the less you need to whiten a colour. Titanium whites are best for large areas of white. The zinc whites are more of a mixing white. They will not white-out your pigments too strongly, and so your colours will go further.
As for blacks, start out with one if you like, but the black you make from a dark green, dark red and a dark blue will have much more richness. What about all the other pretty colours? Glorious aren’t they? They’re like candy to us artists. We’re often tempted to play with new colours. Again, we recommend that you get familiar with your core colours and experiment or play with new ones a few at a time. This way, you’re more likely to best understand each particular pigment’s qualities. You will not be gambling with untried colours when a part of your work requires some exact hue.
For more information see Manny’s art blog or talk to one of our team.