webui should distinguish locked and in-progress builds

I'm trying out buildbot based on the the tutorial on buildbot.net, using buildbot 0.9.6. I added a builder and a worker with a lock to prevent simultaneous builds from running on any given worker, then queued a couple of builds. The web ui shows both builds flashing yellow, and when viewing the build page for the second build, it's waiting to acquire locks.

Expected result: display pending builds with a different colour to active builds. IIRC pending builds are shown as grey in older buildbot installs that I have used previously.