[Feature]: Compatible with the terminal software's xterm ANSI - with 256color mode

Is your feature request related to a problem?

There are some compatibility issues between WTIR and SecureCRT's xterm-color.

When TrueColor mode is selected, some remote hosts exhibit the following display issues.

When xterm - ANSI with 256 colors is selected, the screen shows no color, and the selected line does not have a highlighted background color.

The remote Linux terminal has TERM=xterm.

Describe the solution you'd like

Could you consider implementing a fallback that uses white background with black text to highlight the selected line when the terminal software does not support TrueColor?

Additional context

No response