Xinit and Chromiumbrowser Background-Color

Hey everyone,

i work on a project and use dietpi as os. I use the Chromeium-Browser with a touchpanel to control the Pi. On boot, the Pi shows a custom splash screen and a custom background color.

The problem starts with /var/lib/dietpi/dietpi-software/installed/chromium-autostart.sh. The screen turn black, some short white flickering and starts loading the webside. I would like to have the start of Chromoium browser not directly on the screen. Is it possible to start it and show it on my Display after 4 seconds? Or is it possible to define a background-color while starting chromium?

Regards
splitti