Stylize only part of text conditionally?

[rieje]

I have disk size stylized conditionally depending on whether it's getting full (red means getting full as in the drive on the right):

Is it possible to stylize the text separately? E.g. don't color the name of the drive "D2"--only color the size of it or better yet a border so the foreground/background of the text remains the same whether or not the disk is full (for readability purposes).

My current style.css:

#disk.downloads.high { background-color: #eb4d4b; color: #000000; }

My current config:

"disk#data": {
    "interval": 30,
    "format": "D1   {free}",
    "path": "/data",
    "on-click": "pc /data",
    "states": { "high": 99, },
    "tooltip-format": "{used}/{total} ({percentage_used}%) on {path}"
},
"disk#data2": {
    "interval": 30,
    "format": "D2   {free}",
    "path": "/data2",
    "states": { "high": 90, },
    "on-click": "pc /data2",
    "tooltip-format": "{used}/{total} ({percentage_used}%) on {path}"
},

Much appreciated.