colour logic..

How is white colour formed in actual sense of objects/materials/things bearing the colour 'white' ?
i guess its inherent to nature of material. for eg white paint may be formed from lime or chalk
white cloth formed from white yarn and yarn formed from cotton, which is inherently white etc..
Can white colour be made...?
Anyone can add views to this ...

[according to colour theory white colour is the mixture or blending of all colours , but if we blend colours it turns out to be black . and black is understood to be as absence of all colours...]