Is it acceptable to use RGB colors when designing HTML emails

It is best practice to stick with HEX colors when designing HTML emails - does it matte开发者_运维知识库r?

HEX are RGB colors.

If you are talking about color: #010203 vs color: rgb(1,2,3) in CSS, it doesn't make any difference. But some HTML mail clients will not allow you to use arbitrary CSS anyway.

When colors are specified in the HTML itself (eg. <table bgcolor>), only the #010203 format is allowed. Specifying colours in HTML is a vile horror that only really still exists because HTML mail is so fundamentally broken.

In general it's always best to use hexadecimal values [ie: #333333] for HTML emails. Lotus Notes 8.0 will ignore your entire inline style declaration if you use RGB decimal values [ie: rgb(x,y,z)] and Hotmail will not support RGB when defining border colors.

Here's a breakdown for each email client.

Some built-in WYSIWYG editors (like Dreamweaver and FrontPage) output RGB values so it's always good to test your design in all email clients before sending your final email. Here is a great tool for testing emails: Email on Acid.

Assuming you're referring to the declaration format rgb(x,y,z); I believe that's a 2.1 feature and since browser support for that is incomplete coughIEcough I would recommend avoiding it for email clients which in general are considerably further behind the curve than browsers to put it mildly.