Oh, I get it now. O and N refer to backbone atoms only, so to color sidechains I would have to refer to each sidechain nitrogen and oxygen group specifically. Any shortcut for this in ChimeraX? Do I have to define a named selection?

On Thu, May 30, 2019 at 7:06 PM Liz Kellogg <lizkellogg@gmail.com> wrote:

Hi,

There used to be this handy command in Chimera to color oxygen atoms and nitrogen atoms specific colors:

color @O red,a
color @N blue,a

but I can't find the corresponding command in ChimeraX. Is there a way to color all nitrogen atoms blue and all oxygen atoms red?
When I try what I think the equivalent command should be (I'm displaying cartoon backbone with stick side chains):
color @O red target a
color @N blue target a

it says 'Colored 1120 atoms' but none of the sidechains are colored differently.

Thanks for the help

Liz