I observe the following error in the Beta Version of 1 Password 7 for MacOS: for some of my custom rich icons the transparent background is displayed in black instead of white (refer to the screen shots). This error only occurs in the MacOS Beta. The latest MacOS release V7.2.2 and all Windows based versions of Version 7 (including Betas) and even 1Password 4 show the icons with white background.
Unfortunately I cannot trace back how these icons where populated. With 1Passowrd 4 I used 16/32/64-Pixel ICO-Files (due to the 32K size restriction). Sometimes (under MacOS) I dragged PNG-files with better resolution into the items.
1Password Version: 1Password 7 V7.2.3.BETA-7 (70203007)
Extension Version: Not Provided
OS Version: MacOS Sierra V10.12.6
Sync Type: Folder