[BUG] OpenCode TUI shows blank/white screen when run inside Voltius terminal (Windows)

[hanumin]

Description

When running OpenCode (v1.18.31) inside a Voltius SSH session on Windows, the OpenCode TUI renders almost completely blank/white. Only the center logo (3 dark squares), faint prompt text, and some hints are visible. The normal interactive interface does not appear.

This looks like a terminal capability / rendering issue (possibly related to TrueColor or advanced TUI support, similar to #118).

Steps to Reproduce

1. Open Voltius on Windows.
2. Connect to an SSH host.
3. Run opencode.
4. Observe the main area is blank/white with only minimal text and logo.

Expected Behavior

OpenCode TUI should render fully as it does in other terminals (Windows Terminal, etc.).

Actual Behavior

Most of the screen is pure white/blank. Voltius sidebar still works.

Screenshots

(Đính kèm ảnh bạn gửi)

Environment

• Client OS: Windows
• Voltius: (điền version của bạn)
• OpenCode: 1.18.31
• Connection: SSH
• Theme: Voltius Light

Additional context

OpenCode is a modern TUI that relies on rich terminal capabilities. Possibly related to how Voltius handles terminal features over SSH.

[kipavy]

OpenCode picks its light or dark colors by asking the terminal for its background color when it starts. SSH sessions in Voltius run inside tmux by default (persistent sessions), and tmux before 3.4 doesn't pass that query through or reply to it. So OpenCode gets no answer, assumes a dark background, and draws white text on the white Voltius Light background.

Reproduced with OpenCode 1.18.31:

Host tmux	OpenCode colors
no tmux	light ✅
3.2a (Ubuntu 22.04)	dark ❌
3.3a (Debian 12)	dark ❌
3.4 (Ubuntu 24.04)	light ✅
3.5a (Debian 13)	light ✅

GNU screen (used when tmux isn't installed) doesn't reply either.

Can you check tmux -V on the host?

Workarounds, any of these should work:

• upgrade tmux to 3.4+, then run tmux -L voltius kill-server on the host so the old server goes away (this closes all Voltius sessions on that host) and reconnect
• disable persistent sessions for that host: edit the connection, Advanced, Persistent session: Off (the shell won't survive disconnects anymore)
• use a dark theme in Voltius

We could make older tmux reply by pushing the theme colors into the tmux session, but that goes stale when you change theme and doesn't work well with shared sessions, so I'd rather not unless a lot of people hit this.