A pigment, dye etc added to something to change its colour or hue
A small added amount of colour; (by extension) a small added amount of some other thing.
The degree of vividness of a colour; hue, shade, tint.
To add a small amount of colour; to tint; (by extension) to add a small amount of some other thing.
To change slightly in shade due to the addition of colour; (by extension) to change slightly in quality due to the addition of some other thing.
To affect or alter slightly, particularly due to the actual or metaphorical influence of some element or thing.