[Remind-Fans] Adjusting width for ANSI sequences in calprefix/calsuffix

[Tim Chase]

Playing around:

  FSET calprefix(x) "X:"
  FSET calsuffix(x) ":Y"
  MSG "this is a very important thing"

when invoked with "-c+" all my very important reminders are wrapped
in "X:...:Y".

However, if I use ANSI sequences for color,

  SET Esc Char(27)
  SET Red Esc + "[0;31m"
  SET Nrm Esc + "[0m"
  FSET calprefix(x) Red
  FSET calsuffix(x) Nrm
  MSG "this is a very important thing"

things go all bonkers.  My intuition says that remind is calculating
the length of the string (+7 for the prefix, +4 for the suffix) and
using that to align the grid, but by my strings are 11 chars longer
than the actual output.  I know bash lets me wrap stuff in my $PS1
with

  \[{non printing stuff here\]

to tell it to discount the length of anything in between.  Is there
something similar for remind? Or some other way to do this that I've
missed?

Thanks!

-tim