The current RStudio preview release supports colored text in the R console. That means you can do pretty cool stuff with command line output. The downside is that its hard to come up with designs that looks good on light- as well as dark-background-consoles.
For this reason I started developing colt, which is a very thin abstraction layer over the crayon package. The main idea is to use (for example) colt::clt_chr_accent() instead of crayon::red() to emphasize text. What color colt::clt_chr_accent() actually has is decided by a color theme (basically a list of functions) that can be easily switched.
The functionality of colt is more or less complete; however, I am still not sure about the selection of theme elements I chose. I welcome any input regarding the naming and number of theme elements (should there be more? should there be less?).
There is a short vignette with example images and a full list of theme elements here: