TinyDNS escape character

[com2]

I try to add a spf record to my TinyDNS zone. The text record has the
following syntax:

 '  :fqdn:s:ttl:timestamp:lo

As you can see the colon (":") is used as separator but it is this
character that is also used in the actual spf record text. I tried to
use backslash as an escape character, but this doesn't seem to do the
trick:

'serverclone.com:v=spf1 a mx ip4\:78.47.172.146 mx
\:mail.serverclone.com ip4\:78.47.172.147 ~all

When I restart the server and check with dig, no TXT record appears.
Anybody knows the escape character that can be used? Or am I doomed to
use only the simpler SPF records? Any ideas?