Root and plant initial style, try and keep the style consitant when creating your organic assets so refer to this as reference or whatever. Also below are two colour swatches for you to use, one for the roots colour scheme and one for if you're texturing another red plant (obviously not all the plants are gunna be red!). You can grab the colour table files (.act) off the Plant and Root folders in Asset_Source>org on Kdrive to load them in photoshop.
So yes, always use the root colour pallet when texturing roots! :)