How Color Affects Taste and Smell :-

This relationship between colors and mind known as  "synaesthesia" . This condition describes how our senses work together.

 For example - with respect to sight, taste and smell - seeing a color may evoke any number of other sensations. Green may be evocative of the smell of grass, lemon yellow may evoke a sour taste.

This is best understood by the fact that each sense has a pathway to the brain. These paths are parallel to each other.

In situation only seeing by colors it stimulates the sense for taste . 

• Seeing the color yellow-green may evoke(conscious mind) taste sensations of sourness
•  pink may evoke sweetness. 
• Seeing the color grey may evoke olfactory (smell) sensations of smokiness.

We all have some degree of synaesthesia. However, a person with a strong sense of synaesthesia senses stimuli different from a "normal" person. For example, to the person with synaesthesia, a color might have a "taste", a sound might be "felt", and a food might be "heard".