When white light strikes an object, each individual frequency of light is transmitted, reflected, or absorbed, depending on the properties of the surface molecules. If all frequencies are absorbed by the object, then it appears black. If all frequencies are reflected, then it appears white.
A red object is red when white light falls upon it because it absorbs all the components of white light with the exception of the red component which is scattered.
Reference link
https://www.le.ac.uk/se/centres/sci/selfstudy/lac4.htm
The light that is reflected is the colour of the object in that light. For example, a blue object absorbs all the colours of the spectrum except blue: it reflects blue light. ... Objects appear black in white light because they absorb all colours and reflect none.
Reference link
https://www.bbc.co.uk/bitesize/guides/zq7thyc/revision/6
