iMac black screen after startup chime, but before Apple logo

[PilotTiny]

Hi all,

I am writing here with a very little (but incredibly annoying) issue that I am having with my late 2013 21.5 iMac. I updated to Yosemite, which has the new boot screen with the black background and the progress bar. However I decided I didn't like the design of Yosemite so I reverted to Mavericks.

Mavericks installed fine, however the annoying thing is that now when I press the power button, the screen stays black after the startup chime, and then turns grey when the Mavericks boot screen shows. I would like to be able to get my screen to display grey the moment from the startup chime sounds, just like previous versions of OS X. Anybody know how to help?

Sorry if its a little confusing, but I hope there are people out there with the same annoying problem that I have.

Thanks,
Ashley

 

[SaSaSushi]

Installing Yosemite on the Late 2013 iMac (actually Ivy Bridge and newer Macs) also applies EFI/SMC firmware updates that change the boot screen to white on black background. Just reinstalling Mavericks will not revert those changes.