Is it me or does it seem to take a lot of color for SMBC?

I need to make a nice, rich chocolate brown. I used quite a bit last night and iced the cake thinking it would darken but it is still not dark/rich enough.

Can I airbrush it? Should I add more color and do another coat of icing?

Any ideas for how to do this without making a mess? Suggestions for the future?

TIA, I appreciate your help!

Definitely cannot airbrush SMBC. And, what did you color it with?

Glad to know the airbrush is a no. Thank you for replying! The cake did darken up quite a bit since then. So, I think it will be okay.

I almost always use Americolor gel in the squeeze bottle. It just seems to take a lot of color to get darker shades sometimes.

Thank you for your help!