Go into dashboard, themes, and click on customize next to dark chocolate and you should be able to change it there

yes I can change the colour here but not the font or size

guess I found the answer myself, for anyone who cares to know, I just edited inside the main.css of my theme:

#page #header ul.nav-header li{float:left; padding:2px 0px; margin-left:16px; margin-bottom: 0px; color:#999; font-size:16px; margin-top:0px }

change font-size for header nav

and

#page #central #sidebar ul.nav{ list-style:none; margin-left:0px; padding:0px; padding-left:24px; font-size:16px;}

for side bar nav

oh and somwhere quite near there I changed the font family as well

How do I access the CSS?

IN the root of your installation go to concrete/themes. In there it has the bundled themes and each ones files. So if you wanted to edit the Dark Chocolate css you would go to concrete/themes/dark_chocolate. In that folder lies your main.css. Copy it to your computer. Edit. Reupload to the same directory and overwrite.
If you are wanting to edit a theme that you've added from the marketplace, chances are its in a package. The same steps apply as above but the location is different.
root/packages is where marketplace addon's are placed.

Love it when a solution works! Thanks for the info.. Ted

I'm new to Concrete5, but am an experienced web developer. I like the general "click & edit" trend of concrete5, but constantly run up against the need to change things that don't work that way, as with auto nav. In my case I wanted it to be left justified rather than right justified.

I can easily edit the css to accomplish that, but is doing so in keeping with concrete5 philosophy? Is this type of thing common in concrete5?

In my opinion if you simplify website design you will sacrifice flexibility and customization. When every little thing can be tweeked & adjusted you will not have a concrete5 CMS but something more like dupal, joomla or wordpress.

I really like the click to edit concept, but wish every little detail was available to be edited within that context.

Just about every developer has their own favourite custom templates, either developed by themselves for themselves, for the marketplace, or from the marketplace, from scratch or a minor tweak of an existing template.

One of the great things about C5 is that if you cant find a template that suits you or can be adapter, custom templates are pretty easy to create and you only need to know the basics of php and css to do so.

Actually you can do a lot without any knowledge of css and htmal or php
When you click on a block to edit it, you will see that there are more options than just edit. If you go to "design" you can set alignment, spacing, background color or image, border, ...
From here you could align the auto nav to left just by a click.

Excellent point. I so often use block design for other blocks and completely forget it exists for Autonav.

Not in my c5 using the Greek Yogurt theme.

Oh I see the properties as you described them, and indeed I tried to use them and changed the font and justification. Clicked Save button to close design edit panel, then published the changes. None showed up.

There is a note at the bottom of the design edit panel saying: "Note: Styles set here are often overridden by those defined within the various block types."

I thought this was the process to edit those styles. Why don't the changes show up in the auto-nav.

This worked great on my dark choc theme. You saved me a lot of time. Thanks!