Make arrows of U shaped conveyer a lot darker

When the u shaped conveyer is filled with slag it can sometimes be difficult to tell, especially if it isn't moving. Making the arrows more visible might fix this.

When hovering over belts and pipes, a green arrow showing the direction would be helpful. Currently, I can't zoom in enough to see the arrows properly. A closer zoom would help with that.

Especially while still in construction/planning you cannot see the arrows at all