[BUG] UI regression in v1.2581.0 — flat output, missing table dividers

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

After updating to Claude Code 1.2581.0 (f10398, build 2026-04-14), the CLI output became significantly harder to read.

After updating to Claude Code 1.2581.0 (f10398, build 2026-04-14), the CLI output became significantly harder to read.

Specific regressions:

1. Tables lost horizontal dividers between rows. In the previous version rows were visually separated and easy to scan; now table content blurs into a single block. This affects every table-shaped output I rely on — file lists, diffs, tool results, structured responses.

1. The warm off-white / yellowish-grey background is gone. The previous palette was easy on the eyes during long sessions; the new neutral/cold background feels sterile and adds to the overall flatness.

1. Icons became microscopically small. Tool-call markers, status indicators, and other inline icons are now hard to spot at a glance — I have to actively search for them instead of scanning. On a normal-DPI display they're almost illegible.

1. The overall interface became flat and visually monotonous. Borders, dividers, background warmth, and weight contrast between sections are all gone. Long conversations feel like one continuous wall of text with nothing to anchor the eye.

1. User messages are now tinted blue, which is a nice touch, but it doesn't compensate for everything that was removed — row dividers, warm background, readable icons, and section hierarchy.

Environment:

• Claude Code: 1.2581.0 (f10398), build 2026-04-14T17:16:40.000Z
• OS: macOS 15 (Darwin 25.4.0)

Impact: reading assistant output is the core loop of using Claude Code — hundreds of times per day. Removing visual structure, warm colors, and legible icons directly slows down scanning and makes long sessions tiring.

Tables should render with horizontal dividers between rows, the warm off-white/yellowish-grey background palette should be restored (or at least offered as a theme option), and icons should return to a readable size. Overall the conversation should retain clear visual hierarchy between turns and content blocks — as it did in the previous version.

If the flat, cold, minimal-icon styling is intentional as a new default, please expose these as toggles in ~/.claude/settings.json (e.g. "ui.tableDividers": true, "ui.iconSize": "normal", "ui.theme": "warm") so users who prefer the previous look can opt back in.

Error Messages/Logs

Steps to Reproduce

1. Update Claude Code to version 1.2581.0.
2. Start any session: claude in the terminal.
3. Ask the assistant to render any markdown table, e.g.:

"Show me a table with 5 rows of sample data."

1. Observe the rendered table in the terminal output.

Expected: rows separated by horizontal dividers, clear visual structure.
Actual: rows run together with no dividers; output feels flat and monotonous.

The issue is also visible in any built-in output that uses tables (tool results, file listings, diffs).

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

unknown — the version immediately prior to 1.2581.0 (auto-updated)

Claude Code Version

1.2581.0 (f10398)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This is a visual/UX regression, not a functional bug — Claude Code works correctly, but the terminal rendering after the update removed visual structure that made output legible.

Key points:

• Tables no longer have horizontal dividers between rows.
• Conversation turns have less visual separation, making long sessions tiring to read.
• The new blue tint on user messages is a welcome touch but does not compensate for the lost structural dividers.

Attaching a screenshot of how tables currently render in 1.2581.0. Happy to provide a comparison screenshot if a previous-version rendering is helpful.