Challenges of Making Movies of RGB LEDs

RGB LEDs produce a highly concentrated source of light. They tend to
saturate the videos made of them, so that all colors look the same–i.e., white.

The demos below show what happens when you try to display the colors of
the rainbow using an RGB LED directly, and the using an RGB LED that is
covered by a tennis ball. (But be aware that the tennis ball has a seam in
it which looks like a dark mark around the middle of the ball.)

Looking at the RGB LED directly

The video should show colors smoothly varying from purple, through blue,
green, yellow, and red, but some colors are so saturated that they just
look white.

Looking at the RGB LED through a mask

The mask is just a tennis ball with a hole drilled in the bottom.

The problem of saturation is much less in this video because the light is
diffused over the surface of the ping pong ball.