UX: Color coding the transfers with different status on the 'Downloads' tab

[501NotImplemented]

Describe the solution you'd like

As a user, I would like to have the ability to highlight the transfers of different statuses by different colors (just like in the original Soulseek client), to visually separate them in the grid and have a better user experience.

As of now, the only way to anchor the attention is the transfer progress bar, however the color of transfer in unfinished status (<100%) and completed (100%) is the same, blue one.

Additional context

Basically, after migrating to Nicotine+ from Soulseek QT, I miss the color coding of different downloads on the downloads tab. It would be much easier to visually separate them on the grid, the SoulseekQT color theme will work perfectly for me.
E.g.

• Finished - green
• Connection timeout, canceled - red
• User logged off - grey out
• Queued - light blue
• Transferring - black