If you do not already have a colour scheme in mind, based on your logo or branding for example, then you could use one of the suggestions further down this page as a starting point.
Unless otherwise stated, the colour palettes are composed of a main colour, its adjacent colours and its complementary colour, based on an RGB colour wheel.
Using all the colours in every row is likely to look pretty garish but, for example, if you wanted a monochromatic scheme you would use the colours in one row only. For a two colour scheme, you could choose colours in two rows.
Using rows 1 and 4 gives a complementary colour scheme.
Row 1 with either row 2 or row 3 results in an analogous scheme.
Row 4 plus row 2 or 3 forms part of a split complementary scheme.
This example is based on the “Morning Glory” palette.
Suppose I wanted a complementary scheme with just a couple of light and a couple of dark variations of each colour. I could use the lightest two colours from rows 1 and 4 and could visit color-hex.com to extend the scheme and find some darker shades. To get some light and dark greys, I could use a photo editing application (in my case I’ve used Paintshop Pro) to adjust the saturation and lightness of row 4.
The colour schemes above have been generated using the color-hex.com website. More shades, tints and monochromatic colours to supplement any of these schemes can be found by entering a hex code into that site. Colour names are based on the Chir.ag name that color project and are included to make it easier to reference a scheme.