GNS3 v1.2.3

1. To change default theme
Edit -> Preferences -> General
General Tab -> Style -> Legacy

Old

New



2. Edit console style
Edit -> Preferences -> General
Console applications Tab - > Console application command:

putty -telnet %h %p -title "%d" -sl 2500 -fg yellow -bg BLACK -fn "client:Monospace 12" -fb "client:Monospace Bold 12"