It sounds like you want to get round the limit of the default settings for databars, i.e. one colour for positive values and optionally a second colour for negatives.
It's actually possible to set separate conditions manually with different-coloured databars for different value ranges. You just have to be careful with the order they appear in the list of conditions.
You might want to have a look at an add-on I made a couple of years ago. It opens a form that does it all for you. And you can set a load of options for each range of values, like solid/gradient, with or without label or border.