You can choose to have the colours of your wig blended or streaked.
Blending is a mix of 2 or more colours. The colours can be mixed to an equal ratio 50:50 or different ratios depending on whether you wish to have a dominant colour. In the example shown here, there is an equal mix of colours.
Streaking means random streaks of specified colour(s) to fringe, front, back and sides as made by the factory.