Hexadecimal vs. RGB Values in HTML Emails

We had a recent question in our forums regarding which clients support hexadecimal vs. RGB values so I figured I would publish the results of my research to our blog as well.

In summary, it is best to avoid using rgb(255,0,0) values when developing HTML emails. Long hex (#F00F00), Short hex (#F00) and colors (red) are supported in all the email clients I tested.

What I found interesting is that some clients support RGB colors on fonts but not in backgrounds or borders. I should point out that I used inline CSS in all of my testing.

The clients that do NOT offer full support for RGB values are: Hotmail, Lotus Notes 6.5, 7 and 8.

As you can see, my primary focus was on hexadecimal vs. RGB and I used inline CSS. I will research background colors and images – defined by inline CSS vs. HTML attributes in another post.