No. The red and blue blended become magenta.
The green and red become yellow and
the blue and green become cyan.
The combinations are the secondaries, different from say oil painting, but this is actual light waves.
Yes, they are considered subtractive in photo finishing. You subtract more of the secondaries to increase their opposites. In additive methods you have to do 3 separate exposures, (like color printing in magazines), of each of the primaries. This is a dying technique, so don't worry if you don't understand.