Connections
Puzzle #920
🟪🟪🟨🟪
🟪🟪🟪🟪
🟨🟨🟨🟨
🟦🟦🟦🟦
🟩🟩🟩🟩

I was not expecting blue to be blue... It was the first connection I saw (after the red herring) so I thought it would be much lower on the scale.

Also I had never heard of "shell" in that context.