I think you mentioned that light multiplies by the color of every surface it hits. If I am understanding this correctly, the light rays (1,1,1) shoot from the light source as white, then if it hits the surface of a plane that is pure yellow with no blue (1,1,0), the blue portion of the white light rays that shot from the light source gets multiplied by 0, which is why the surface would appear yellow. Is this correct? Thanks.
That is absolutely correct jjohnnynitro1234
The RGB values are being multiplied componentwise. In your example, the blue light gets completely 'absorbed' by the surface and all the red and green light rays get completely reflected. (This is why you should avoid values close to 1 for the RGB channels when making realistic materials (with the exception of glass and lights themselves), because some light always gets absorbed and light rays that have bounced around a few times, should hardly contribute to the scene lighting anymore.)
(The simple multiplication of the RGB values works here, because Blender uses linear colorspace, so for instance: 0.5 x 0.8 = 0.4. This is not always the case in other software.)