we can see white when a substance reflect every colour ...and if we are looking red colour it means that the substance is reflection red colour...so when a substance is reflection every colour can we call it a colour ????????
This is very Basic Physics question ! Sunlight is composed of colors ( a spectrum - http://www.lunarplanner.com/Harmonics/Planetary%20Harmonic%20Charts...) ....thus the Rainbow ( the prismatic rain drop splits the individual frequencies ...each frequency is a different color ViBgYoR ( Violet , Indigo, Blue, Green, Yellow, Orange, Red ). Now experiment this put all these colours individually on a circular disc ( 51.42 x 7 = 360 degrees )...rotate the disc you will see a white disc !
When you go to buy a White Suzuki Baleno and friends ask you ? what color is your car ! what will you say ? :)
When a client tell you " I want a white room ? " ...what will you paint it ? Red ! :)