Stepper motor boost gauge with remote electronic pressure sensor, with aluminium vent holder for easy fitment. It's in the right colour (white when on, orange with headlights on) and it took me a while to find. It has a programmable warning with a loud beep and the gauge goes red if you go over the max boost that you've set.
Pics:
Off

On (disregard the 2.0BAR reading, I didn't have the boost sensor connected)

Headlights on (you don't have to wire it in to the headlights if you prefer it to stay white)

Peak boost warning

£60 posted.
Pics:
Off
On (disregard the 2.0BAR reading, I didn't have the boost sensor connected)
Headlights on (you don't have to wire it in to the headlights if you prefer it to stay white)
Peak boost warning
£60 posted.