Change the Anchor Text Displayed in Category Tree, but NOT the Category Name

I'm just wondering if there's an easy way to change the anchor text that people click, to take them to the individual categories on site. For example, look at www.silkblooms.co.uk:

We have a colour filter set up on the left hand side, below the main categories:

Colour Filter:
-White......-Ivory
-Cream......-Pink
-Peach......-Orange
-Purple......-Red
-Green......-Yellow
-Silver......-Gold
-Brown......-Black
-Tartan.....-Grey
-Aqua......-Blue

For SEO pruposes, it would be so much better is these categories were re-named to "white wedding flowers", "cream wedding flowers, "peach wedding flowers"...... and so on. However, changing the category names will also change the anchor text, in the category tree on the website.

Is there a way to control the anchor text, so it can be different from the category name?