In the upper middle of the ChessTask window you can see the three "areas" Pieces, Color and Selected.
Pieces contains all the normal chess pieces. I added two symbols, a cross and a circle, that can be used for marking special points on the board. These could be: "weak points", "entry points for the king", "the correct square for a checkmate" a.s.o.
You can select a piece by clicking on it with the left mouse button. Then it gets displayed in the field Selected.
Color offers the two colors "Black" and "White". If you change the color by clicking on it with the left mouse button, the selected piece is altered accordingly in the Selected area. The cross marker and the circle always look the same, regardless of their color.
Selected displays the currently selected chess piece.
You can set this piece onto the board by pointing to a square and clicking the left mouse button (If you do not see a chess board to the left, insert a new task by using the leftmost toolbutton Insert Task). Nonempty squares get overwritten. The right and middle mouse button erase a square.