If you're one of those people who have customized their entire home screen to be shamrock green, and having this different coloured block there is giving you an aneurysm, look no further.
From the shortcuts app, tap the three dots in the top right of the shortcut
Once the shortcut is opened, tap the icon in the top left.
If you're still confused, you can check out Apple's instructions on how to modify shortcut colours and icons.
The Virtual Schedule shortcut will appear by default in your Apple Watch shortcuts app. To be a productivity wizard, you can also add a complication for the shortcut which will appear on your watch face.
If you aren't sure how to do that, check out Apple's instructions on how to customize the watch face.