Adjust your Citrix Policies to allow 24bit or higher color depth.
The location of this Citrix Policy setting is under:
ICA/Graphics > Maximum allowed color depth – (set this to anything above 16bit)
NOTE: The default setting for Maximum allowed color depth is 32bit.
This issue is listed for Receiver for Chrome 1.6 under the Known Issues section of the release notes.
“When a session is launched using XenApp 6.5 with maximum allowed color depth set to 16 bits per pixel, a black screen results. [#0552507] ”
Default policy settings
Citrix Forum posting – HTML5 Application shows only black Screen