However, my site is still resizing up and down if you reduce or expand the browser width, but that's not a problem as it looks OK

This is expected—it's how the theme was designed to work.

my problem is when you view it at a narrow screen width, e.g. ipad size, at which point the second column moves to flow beneath the first column and converts to a black background - presumably to make the distinction of the second column

Take a look at the @media rule for the 900 px max width here:
https://s1.wp.com/wp-content/themes/pub/reddle/style.css?m=1356723415g&minify=false

You'll notice there are a few rules that set the background color to black. To override those, copy the @media block, remove everything but the rules for the colors, and replace the color values. Here is an example to get you started:

@media (max-width: 900px) {
	#page #main .widget-area {
		background: #fff;
		color: #000;
	}
	#wp-calendar caption {
		color: #bbb;
	}
	#wp-calendar tbody td {
		background: #fff;
		border-color: #fff;
		color: #bbb;
	}
	#colophon,
	#supplementary {
		background: #fff;
		border-color: #fff;
		color: #000;
	}
	#page #supplementary .widget-area {
		background: #fff;
		color: #000;
	}
}

#pagenav a {
border-bottom: 4px solid #D7BCED;
}

This is the dark purple (hover/current page item)

#pagenav li.current_page_item a, #pagenav li.current-menu-item a, pagenav li.current-menu-ancestor a, #pagenav li a:hover {
border-color: #3B0466;
}

Also note that Bueno has been CSS edited by others and you may find the answer to your questions by searching. http://en.forums.wordpress.com/tags/bueno

I and using a Bueno theme, and would like to change the colour of the line underneath my menu of pages along the top of my blog to #46C7C7. It is currenlty purple.

Please can you let me know if this is possible and if so, how to achieve this. I would also like to insert a header and hide my title which I was told you can now do.

Please help - thank you

Claire

wp.com sends your custom CSS to the browser after it sends the theme's own CSS, so your custom settings override the corresponding settings from the theme's own CSS.

-- Graham

... I can testify that in many hundreds of uses of wp.com's Edit CSS feature, it has never once not done what it's supposed to. Now the CSS might not produce quite the effect I expected in the browser, but that was always because I didn't yet understand some aspect of CSS or browser that I later saw was the cause, and was able to remediate.

-- Graham

http://csswiz.wordpress.com/2009/10/15/if-you-have-the-wp-com-css-upgrade/

body {
background:#acacac;
font:normal 1em Arial, Helvetica, sans-serif;
margin:0;
}

What you would add to the CSS edit window to change the background color would be:

body {
background:#acacac;
}

and then change the hex color code.

Without knowing the exact code you edited and which theme you used it is impossible to tell what could be the cause or why things did not work out as expected.

For some reason, no matter what colour I change, when I preview the CSS as either new or add to existing, I see the colour change but also different areas are within the template seem to get effected in the layout and things are not where they should be. This is probably the easiest task you can do in CSS so I am confused!!

Why is this happening and what guarantee do I get that if I go ahead and pay for CSS Upgrade, that this wont happen once I have paid for it?

Also I would like to insert a logo next to the text and want to know if this is possible and what code I would need to create to do this.

If either of these are going to be tricky with the current template is there any better ones for doing this?

thanks

I am not suggesting you should switch to firefox for good - I wanted you to try it in firefox (or any other browser except the one you are using) to see if it worked there. If so, it's a browser problem. If not, then it would be important to notify staff.
See? It's called problem determination.

Update the browser you are using.

And personally, I'd prefer a browser that worked for the things I wanted to do. Browsers are not really that diffrent - you'd get used to it.

i can't write it more clearer than this, sorry!
and it is only when i want to change the colour of any bit of writing...

-you have trouble with editing. Apparently, strange things happen when you try to format text.
-you want the links to stand out even more that what they do (how?! they're uppercase, fire engine red and bold).

If this is not correct, please correct me, and please be succinct.

There used to appear a message when you wanted to change colour, now that message doesn't come up anymore (thanks heaven), but now this jumping back of the pointer...

Links in WordPress.com blogs generally ARE a different colour from the background.

What browser and version are you using?

Are you trying to change the colour of the LINKS, or just add them?