When a branch with leaves is broken from the tree and put in the blue-colored water, the color of the leaf changes to [[1]].

The change in color of a leaf when a branch with leaves is placed in blue-colored water is due to the process of transpiration. Water is conducted from the stem to all parts of the plant, including the leaves, through a system of interconnected vessels. When the branch with leaves is placed in blue-colored water, the water is absorbed by the stem and transported to the leaves. As a result, the blue color of the water is visible in the leaf's tissues, causing the leaf to change color to blue. This occurs due to the transpiration pull mechanism, which draws water up from the roots and into the leaves, bringing with it any dissolved substances, including the blue-colored dye.