1 - it consistent with what appears to be the approach of the K500 model Hexa are featuring right now.
2 - it is a small touch that distinguishes the brand from others.
3 - assuming the markers are indeed 3-dimensional, lacking a grey border, they will appear to "float" on the dial rather than be affixed to it.
4 - Hexa have blackened out a part of the hour hand on the K500, so this would be yet another application of that design theme.
I definitely think the idea of doing the "300M" in red is a great idea. (Someone above suggested it.)
All the best.
...my desires run not before mine honour, nor my lusts burn hotter than my faith.
- The Bard, The Winters Tale