The white transparent guides of a Building Guide block can be really difficult to see against white backgrounds. I'd like to suggest the ability to either:

1. Sneak + Right Click a placed guide with a valid dye to change the color
2. Have 16 recipes to make guides of different colors using stained glass

I think the former would be preferable, but either option is entirely valid.

Thanks for the suggestion. I might look into something for 1.7.