Error outputting 24 bit color gradients

[splitDEV]

Describe the bug

I stumbled upon wezterm and I really like it so far. Thank you for your work and time.
I tried some things and unfortunately displaying 24 bit color gradients resulted in nothing being shown, despite true color support seems to be working for normal text output using escape sequences:

Environment

• OS: Archlinux
• Version: wezterm 20210502-154244-3f7122cb
• ENG

To Reproduce

Run the following script in wezterm: https://github.com/csdvrx/sixel-testsuite/blob/master/24-bit-color.sh

Configuration

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Expected behavior

Left terminal wezterm, right terminal kitty:

[wez]

That script uses a non-standard encoding for true color. There's a complicated back story, but it boils down to
a sequence such as ^[38;2;<r>;<g>;<b>m (where the 2 is the rgb color space, and the values are semicolon separated) as being the standard. Some terminals mis-implemented that using : for a separator, and then again an implementation of that which omits the 2 (color space) parameter is floating out there.

The script is using SEPARATOR=: even though its comments use ; at the top of the script.
If you change the script to set SEPARATOR=; on this line https://github.com/csdvrx/sixel-testsuite/blob/master/24-bit-color.sh#L11 it will render the color sequence correctly.

I've pushed 3d83a80 which also allows recognizing the sequence used in that script.

[splitDEV]

Wow thank you for the quick response and fix :)

You're doing outstanding work!!

[github-actions]

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