I would like to have a if-else loop in **.screenrc** for the following codes such that it is run if my terminal supports 256 colors. Otherwise, it is not run.

```
attrcolor b ".I"
# tell screen how to set colors. AB = background, AF=foreground
termcapinfo xterm "Co#256:AB=\E[48;5;%dm:AF=\E[38;5;%dm"
termcapinfo xterm-color "Co#256:AB=\E[48;5;%dm:AF=\E[38;5;%dm"

```

**How can you make the if-else loop in .screenrc?**