Visualization also works through harmonics. Visualization is harmonics.
Link from David Hopkins
You will visualize the successive transmission of energy from the base of your being into the highest most refined layer.
The visualization of color frequency tone, will occur alone or with conscious generation of sound frequency tone.
When these combine and erect a visual internal spine overlayed within and around your physical and silent external spine, you will have generated the portion of your light body relative to the sustenance of your existence on the physical plane.