OT can produce mortar star shells with 0,0,0 RGB

## Testmerges
#10999: 'Fix of various plane related issues' by Blundir at commit f85a7153c4
#11661: 'Despoiler rework' by Git-Nivrak at commit c0f8d2884f
#11724: 'Point Blank Refactor [EXPERIMENTAL]' by TrollerNoob at commit 466ad883dc
#11680: 'Don't qdel tgui windows' by Drulikar at commit 0499627b55
#11368: 'FTL Hijack Evacuation' by Drulikar at commit 75c4efe419
#11555: 'Adds tethering to some storage items' by Nihisohel at commit 17401339ec
#8991: 'Medical Rework Phase 1 - Chemical Changes' by Nihisohel at commit cae6f0c929

## Round ID
32704

## Description of the bug
see title, the OT, by loading carbon into mortar shells can make the fire colour 0 which bugs out the fire, causing it to be invisible and emit no light

## What's the difference with what should have happened?
invisible fire which instantly kills boilers is bad and shouldnt exist

## How do we reproduce this bug?
1. create a mortar star-shell and load it with carbon
2. fire it
3. observe that the produced fire emits no light and has no visible sprite

## Attached logs
```
N/A
```

## Additional details
- Author: willzadl
- Admin: the tobiasreaper
- Note: None