Color billed lines on Sales order form

Hi,

I've been thinking about making it more clear to the user that an order line is billed or partly billed. I do have the "Billed" column visible on the form, it is however pushed so far to the right that you have to scroll a bit on a regular laptop monitor to see it.

My idea is to change the background color of respective line to orange if partly billed or red for fully billed. (red to remind the sales reps not to change an order line that is already billed).

I've been toying around with the idea of using a inserted HTML column-field that somehow changes the background color on the full row based on a CASE-formula.