6. Place small balls of red, white, and yellow colors into red, white, and yellow boxes, with each box containing balls of the same color. It is known that
(1) The number of balls in the yellow box is more than the number of yellow balls;
(2) The number of balls in the red box is different from the number of white balls;
(3) The number of white balls is less than the number of balls in the white box.
Then the colors of the balls in the red, white, and yellow boxes are respectively $\qquad$
6. Yellow, Red, White.

From condition (2), we know that the red box does not contain a white ball, and from condition (3), we know that the white box does not contain a white ball, so the yellow box contains the white ball.

Assume the white box contains the yellow ball. From condition (3), we know that the white ball is fewer than the yellow ball, which contradicts condition (1), so the white box contains the red ball, and the red box contains the yellow ball.