I connect with PuTTY (with "xterm") to a Debian system running Informix. In all Informix applications (self-written 4GL as well as
i4gl) PuTTY switches the background and foreground colors when one hits a key that Informix does not understand (like the Del key) or tries to write to long text into input fields. So, grey text on black background becomes black text on grey background. I then have to manually reset the terminal (with either
reset or PuTTY's own reset terminal button) to restore the original colors.
Nothing else happens, just the color change. When the color changed, it does not change back without terminal reset, even when reproducing the first steps that switched colors.
How can I disable this behaviour and what does trigger this? What code is send back to PuTTY from the server to allow color changing of the client?