You can change the colour of solid hatches by editing their properties after creation, but it would make more sense to have that option included in the Hatch creation dialog box… 
Hatches assume the color of the current layer when you create them.
If you are moving them to a different layer to change the color, set that layer to be Current first.
If you’re assigning a color to the object and overriding the layer color, maybe a little command macro would save you the step.
Yeah, it just seems like as you often create multiple hatches on the same layer the Hatch dialog would be the ideal place to add this option…