The essential colors are:
I recommend the Winsor & Newton Artists' Oil Colour line of paints. There are many brands of paint that are equally good (and in some cases better) as Winsor & Newton, but I recommend Winsor & Newton primarily because they are available worldwide.
In addition to the essential colors, if you are going to paint something with an extremely bright red or a strong blue-green color, you may need to "boost" your colors with two additional pigments.
Please be aware that these colors are very rarely used and I would not purchase them if you are on a tight budget unless you know you will need them. I almost never use these colors, and when I do, I only use a tiny amount.
The two "power" colors I use are:
In addition, you will also need a tube of Winsor & Newton Griffin Alkyd Fast Drying Oil Colour in both Burnt Umber and Titanium White, which will only be used for staining your canvas. Do not use these for the actual painting process, and make sure to stain your canvas outdoors or in a very well-ventilated area! Click here for a video on how to stain your canvas.
There are currently no mediums on the market that slow the drying rate of oil paint adequately, so you will need to make it yourself.
recipe for slow-dry medium (for all colors except titanium white):
For burnt umber, you will need extra clove oil. Please watch this video for instructions on how to incorporate the extra clove oil into burnt umber: youtu.be/lpU9egKu-kM
recipe for slow-dry medium for titanium white:
* Venice turpentine is not at all the same as what is commonly known as "turpentine", a solvent commonly used by artists many years ago (and still used by some artists today). Venice turpentine, on the other hand, is simply tree sap — a thick resin which is thick like honey.
† Oil of cloves is sold as "clove leaf oil", "clove bud oil", or simply "clove oil" — any of these forms is fine. You may try looking for it in drug stores, health food stores, or from an online supplier.
Here is a video tutorial on mixing paint with medium: youtu.be/lpU9egKu-kM