Comment out line that is causing issues with layout in editor,
and add a try/catch for case of un-found color values, like
what happens in hint code

Test Plan:
- Load /computing/hour-of-code/hour-of-code-blocks/p/challenge-melting-snowman
- Click around each hint code step and see commands with white blocks inside
- Try changing the background color in the code and see it change

Auditors: john