Set border color for <fieldset> and <legend>

Is possible to alter the border color of the <fieldset> or <legend> tag? You can see them in action here:

I want to change that black border to gray one? Is this possible and what CSS would I need to use? Thank you.

bizarrely enough, it’s the “border” css property :wink:

fieldset {
border: #ff0000 3px solid;

Thank you. I also found another property for the fieldset and that is the

display: block
What other values are available instead of block, I wonder?