Contrast Issues with light Mint-Y theme

[Piiit]

I have some contrast issues in VMWare Horizon Client. I did not include this into issue #21, because it is not one of the dark variants. However, it is related to (and maybe a duplicate of) #52.

The following problem may be related: it's hard to read the volume level via the OSD when using Mint-Y as one's Cinnamon theme. Image (note the dark green on grey; the screenshot shows a low volume level, but the difficulty is almost as severe when the volume level is higher):