Code Master

This is a modification of the well-known game "Mastermind".
The player is given six attempts to guess four-color code.
Each position in the code is one of six colors. Colors can repeat themselves in different positions. As an attempt is made, the player gets the result of the match by means of two-color tags (black and white).
A black tag means the coincidence of both color and position. A white tag means the coincidence of color only. Each position is estimated only once.
Have a good game!