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.
The degree of vividness of a colour; hue, shade, tint.
A small added amount of colour; (by extension) a small added amount of some other thing.