All naturally occuring plant hormones are phytohormones. Want more IBA, increase levels of blue.
Blue light at a wavelength of around 440 nm is most effective for increasing the plant hormone indole-3-acetic acid (IBA), or more generally, auxin. Studies show that blue light promotes adventitious root formation in plants like tea, likely by increasing auxin content and upregulating key auxin-related genes. While red light is important for photosynthesis, it can sometimes inhibit root formation, suggesting a more nuanced role for different light spectra in regulating plant growth and hormone levels.
Don't seem to be the most beneficial hormones to be focusing on.