Colour is a whole new area in drawing and painting which sometimes for some complete beginners I think is best left until they have developed some basic drawing skills. Seeing colour is quite a skill because colour changes depending on changes created by lighting and reflected light.
There is no real easy answer to seeing colour, it takes lots of practice in observation. Learning colour mixing is very important for seeing colour and understanding the minor differences between a ‘warm orange’ and a ‘cool orange’. Often when we start painting, colours just look like one colour and seeing the differences in variation is challenging.