I’m a Korean…so please understand..
I am not familiar with English to explain…^^;;

First..make 3 tracks
1. Text track (color of light)
2. linear Red green and blue
3. Text track (color of text)

Click! 2nd track video media Generator

1. ①,③ click -> make transparent
2. ② click -> make white color
3. ①,③ click and move the mouse to adjust the size of the light.
also controlled by the rotation angle of the light.

1. First track -> Click compositing mode and select Multiply(Mask)

1. Click! Event Pan Corp of 2nd track

1. Movr to Left F box

1. End of timeline click and move to Right F box
2. PLAY –> Effects to be applied will be able to see
More extra Application is your mission
and I’m so sorry for bad description ^^;;