What does the stripes under the weapons icons mean

[ADIGA88]

I noticed there are stripes under weapons icon on the army view, each icon type (like havey machine gun) have it's own color and number of stripes under it. do any body know what's it mean?

[dieman]

You can’t mount a weapon on a slot if this slot has fewer stripes than the weapon.

As an example, Stryker can’t use the recoilless gun. Stryker has a remote weapon system. It uses the same type of weapons (mounted weapon type, green slot), but not all weapons of this type suit it.