Which mixing technique involves using a liquid dye to change the color of flower stems?

The technique that involves using a liquid dye to change the color of flower stems is accurately referred to as stem dyeing. This method specifically targets the stems of flowers, allowing for the absorption of dye through the vascular system, which results in the color change of the stem and, consequently, can affect the overall appearance of the flower as it absorbs the dye through its tissues.

When done correctly, stem dyeing can create visually striking effects, where the color can travel up through the stem to the petals, enhancing the flower's aesthetics. This technique is commonly used in floral design to create unique and vibrant displays.

Other techniques like dip dyeing involve immersing parts of the flowers in dye, while spray dyeing uses a spray method to apply color to the surface. Each of these techniques has different applications and results, but for the specific process of changing the color of the stems through absorption, stem dyeing is the proper term.