I have a category with about 5 extra fields.

One of these extra fields contains a PayPal Buy Now button and I have named the field 'buy:'

What I would like to do is remove the 'buy: text when displayed in the front end.

I can hide all the itemExtraFieldsLabel font using

div.itemExtraFields ul li span.itemExtraFieldsLabel {
color: #FFF
}

So the selectors to this point appear to be correct,

but I am trying to use an attribute selector to hide the field that contains 'Buy:' the code generated by K2 is '<span class="itemExtraFieldsLabel">Buy:</span>' so I have tried using:

div.itemExtraFields ul li span.itemExtraFieldsLabel[Buy:] {
color: #FFF
}

but this doesn't work.

Can anyone point me in the right direction with this?

Also is there a better way to hide the text instead of matching the color with the background?

You will most likely have to have a conditional statement to do this.
in the override where the extra fields and labels are displayed you will need to wrap the label display with a condtional that test for the value of the lable and omit it if true and display it if not...
there may be a way to do it with css but i am not up on that

I thought span.itemExtraFieldsLabel[Buy:] with the[Buy] added gave the attribute condition to the selector but I'm not too sure about it.

It's possible the syntax isn't correct with the selector but I have tried all sorts of ways to achieve this without any luck.

Thanks for the reply anyway.

You cannot achieve what you want without editing the HTML output ( by making a template override). When you do so, you will be able to detect the desired field by it's ID.