CSV Rainbow Column Coloring

Overview

Subtle alternating column colors for CSV/TSV tables to help visually track data across wide tables. Uses perceptually uniform colors (Oklch color space) that work well in both light and dark themes.

Key Files

• src/markdown/csv_viewer.rs - Color generation, blending, and cell rendering
• src/config/settings.rs - csv_rainbow_columns setting
• src/app.rs - Status bar toggle button

Implementation Details

Color Generation

Colors are generated using the Oklch perceptually uniform color space:

• 12 distinct hues evenly distributed around the color wheel
• Very low chroma (0.04) for subtle, non-distracting tints
• Different lightness values for dark (0.25) and light (0.85) modes
• sRGB values are clamped to ensure valid colors

Color Blending

Column colors are blended with the row's base background color:

• 35% column color + 65% base row color (alternating even/odd rows)
• Header rows do not get rainbow coloring (solid header background)
• Blending preserves the alternating row pattern while adding column distinction

Cell Rendering

Cells are rendered using direct painter calls for performance:

• ui.allocate_exact_size() reserves cell space
• ui.painter().rect_filled() paints the blended background
• ui.painter().text() draws the cell text
• No spacing between cells (item_spacing.x = 0.0)
• No spacing between rows (item_spacing.y = 0.0)

Dependencies Used

• palette = "0.7" - Oklch color space and sRGB conversion

Usage

Toggle via status bar button "Colors: ○/🌈" when viewing CSV/TSV files in Rendered or Split mode. Setting persists across sessions.

Configuration

• Setting: csv_rainbow_columns: bool (default: false)
• Location: User settings, persisted to config file