RGB LED Decrease Brightness

I am trying to adjust the brightness of my LEDs, I am using a pipet to take my video signal and convert to rgb, and after the pipet I am using the data to create a pre vis of the led’s in place.

The issue I am having is that the LED lights are far to bright, so I need to lower the intensity, this is fine, but I have 20 or so patches, and don’t really want to lower each one.

My question is, once I have the data output as RGB, is there an easy way to decrease the brightness without altering the colours, ie, if I put a RGB Color Split, and then lower each of the colours with a - node, equally, then onto the DMX, it changes the colours.

Does that make sense?

Multiply (Color)