I am looking for someone to explain how to achieve a subtle gradient in adobe illustrator like the one in this icon.
It’s hard to tell in your example, but it is common for apparently flat icons to gain that extra touch of polish by using subtle gradients.
To get it right you should work with tints and/or shades of a color to build your gradient. I find it easiest to work in the HSB model and carefully adjust the Saturation and Brightness values to step up or down on the gradient scale. You can also plug a base color in at 0to255.com to see a nice range of choices in hex.
In the sample below, you can see that there isn’t a whole lot of room for steps between these two greens. The difference is just enough to give a little light affect to the small circle. The separation between the colors should be greater as the distance of your gradient increases.
Source : Link , Question Author : user1676691 , Answer Author : plainclothes