I've noticed lately that whenever I make a very dark color of royal icing such as red, black, dark brown, etc, that the icing does not seem very firm. Its almost as if the consistency is more fragile than the lighter colored icings. Is there a way around this problem? I normally thin my frosting so it will flow well when doing borders and writing letters.

Help! I have 190 monogrammed cookies due this weekend and they want dark chocolate brown colored lettering on ivory. I just need to find the right consistency to still flow well, yet also firm up enough that it doesn't disentigrate inside the favor bag!

TIA!

I would think that the amount of color is throwing off the proportions in the icing.
For brown, could you use cocoa in the royal to help you achieve a darker color? I've done this before. As long as the customer doesn't mind, it could be your solution.
If not, maybe you could add some additional meringue powder to help balance things out.

Lots of color, especially gel or paste, will significantly change the make-up of royal icing. To avoid this, it's really best to color the royal with powdered color.

If you can't get brown powder color, the suggestion to use cocoa is a great one.

Another option here is to pipe the monograms with melted chocolate (real or candy melts).

Rae