MorningHue

Color Palette

Every color is verified against the warm off-white background (#F1EDE5). Keywords and control flow exceed AAA (7:1), all other syntax colors meet AA (4.5:1).

Background & Foreground

Aa Bb Cc

Background
#F1EDE5

The quick brown fox

Foreground
#444444 · cterm 238 · CR 8.33

CursorLine

Cursor Line
#E4DED6 · cterm 254

// comment

Comment
#949494 · cterm 246 · Subtle

AAA Tier — CR ≥ 7:1

module

Vivid Blue
#0000d7 · 20 · CR 9.08

`define

Dark Crimson
#870000 · 88 · CR 8.86

always_ff

Deep Magenta
#870087 · 90 · CR 7.56

logic

Vivid Purple
#5f00d7 · 56 · CR 7.29

AA Tier — CR ≥ 4.5:1

"string"

Dark Green
#005f00 · 22 · CR 6.82

1'b1

Sea Teal
#005f5f · 23 · CR 6.42

Error

Deep Red
#af0000 · 124 · CR 6.37

a + b

Medium Blue
#005faf · 25 · CR 5.52

my_func()

Dark Teal
#005f87 · 24 · CR 6.06

32'hFF

Dark Golden
#875f00 · 94 · CR 4.90

assert

Bright Purple
#af00d7 · 128 · CR 4.73

import

Vivid Red
#d70000 · 160 · CR 4.62

Code Examples

MorningHue highlights all standard Vim syntax groups, so any language Vim supports works automatically. Here are examples from several languages commonly used in hardware verification and software development.

SystemVerilog

alu_scoreboard.sv

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

`include "uvm_macros.svh" `define TIMEOUT 1000 module alu_scoreboard #(parameter int WIDTH = 32) ( input logic clk, input logic rst_n, input logic [WIDTH-1:0] a, b, output logic [WIDTH-1:0] result ); logic [WIDTH-1:0] expected; always_comb begin case (opcode) 3'b000: expected = a + b; 3'b001: expected = a - b; default: expected = '0; endcase end assert property (@(posedge clk) result === expected) else $error("Mismatch: got %h, exp %h", result, expected); endmodule

Python

regression.py

1 2 3 4 5 6 7 8 9 10 11 12 13

import subprocess from pathlib import Path MAX_PARALLEL = 8 def run_regression(test_dir: str, seed: int = 42) -> bool: """Execute a full regression run.""" test_path = Path(test_dir) if not test_path.exists(): raise FileNotFoundError(f"Test dir missing") for cfg in test_path.glob("*.cfg"): result = subprocess.run(["simv", "+seed=" + str(seed)]) return True

C

driver.c

1 2 3 4 5 6 7 8 9 10 11 12

#include <stdio.h> #include <stdlib.h> #define BUF_SIZE 1024 int process_data(const char *input, size_t len) { char buffer[BUF_SIZE]; if (input == NULL || len == 0) { return -1; } printf("Processing %zu bytes\n", len); return 0; }

Makefile

1 2 3 4 5 6 7 8

# Simulation build targets VCS_HOME := /tools/synopsys/vcs/R-2023.12 SEED := 42 compile: filelist.f $(VCS_HOME)/bin/vcs -sverilog -f filelist.f sim: compile ./simv +ntb_random_seed=$(SEED)

TCL

run_sim.tcl

1 2 3 4 5 6 7 8

# Simulation run script proc run_test {testname seed} { set logfile "logs/${testname}_${seed}.log" if {[file exists $logfile]} { file delete $logfile } puts "Running: $testname with seed $seed" source "configs/${testname}.tcl" }

Bash / Shell

run_tests.sh

1 2 3 4 5 6 7 8 9

#!/bin/bash PROJ_DIR="/home/user/verification" NUM_SEEDS=10 for seed in $(seq 1 $NUM_SEEDS); do echo "Running seed: $seed" if ! ./simv +seed=$seed; then echo "FAILED at seed $seed" >&2 fi done

JSON

config.json

1 2 3 4 5 6 7 8

{ "testbench": "alu_tb", "num_tests": 1000, "coverage": true, "timeout_ns": 50000, "debug": false, "seed": null }

Markdown

README.md

1 2 3 4 5 6 7

# ALU Verification This project contains the UVM testbench for the ALU module. ## Getting Started `make compile` followed by `make sim` to run. [Documentation](https://example.com)

Accessibility & Contrast Ratios

All contrast ratios are calculated against the background (#F1EDE5, luminance 0.849) using the WCAG 2.1 formula. Colors are sorted by contrast ratio.

Hex	cterm	Contrast Ratio	Grade	Usage
`#0000d7`	20	9.08 : 1	AAA	Keyword, module, structure
`#870000`	88	8.86 : 1	AAA	PreProc, `define, `ifdef
`#444444`	238	8.33 : 1	AAA	Normal text
`#870087`	90	7.56 : 1	AAA	Control flow, always, if
`#5f00d7`	56	7.29 : 1	AAA	Type, StorageClass
`#005f00`	22	6.82 : 1	AA	String
`#005f5f`	23	6.42 : 1	AA	Boolean, tag
`#af0000`	124	6.37 : 1	AA	Error, exception
`#005f87`	24	6.06 : 1	AA	Function, Identifier
`#005faf`	25	5.52 : 1	AA	Operator, delimiter
`#875f00`	94	4.90 : 1	AA	Number, constant
`#af00d7`	128	4.73 : 1	AA	Statement, assert
`#d70000`	160	4.62 : 1	AA	Import, include
`#949494`	246	2.60 : 1	Subtle	Comment (italic)
`#1c1c1c`	—	16.29 : 1	AAA	ANSI color15 (bright white) — remapped for TUI tool visibility

* ANSI palette slots color7 (#444444, listed above as Normal text) and color15 (#1c1c1c) are remapped to dark values. On a light background, tools like GitHub Copilot CLI render text in these slots; keeping them light would make the output invisible.

Why Accessibility Matters for Code

Engineers spend hours reading code on screen. A theme with poor contrast forces the eyes to work harder, leading to fatigue and missed details. MorningHue ensures:

Keywords and types are immediately visible at AAA (7:1+), so structural boundaries are never missed
All other syntax meets AA (4.5:1+), the WCAG minimum for normal text
Comments are intentionally subtle so they don't compete with active code
Warm background reduces glare compared to pure white, especially in well-lit offices

Comparison with PaperColor

PaperColor is an excellent theme, but several of its colors fall below the WCAG AA threshold on its own background. MorningHue addresses every one:

Element	PaperColor	CR	MorningHue	CR	Change
Background	`#eeeeee`	—	`#F1EDE5`	—	Warmer, less harsh
Strings	`#5f8700`	3.65	`#005f00`	6.82	+87%
Statement	`#d70087`	4.27	`#af00d7`	4.73	+11%
Operator	`#0087af`	3.56	`#005faf`	5.52	+55%
Numbers	`#d75f00`	3.28	`#875f00`	4.90	+49%
Boolean	`#008700`	4.05	`#005f5f`	6.42	+59%
Broken symlinks	Invisible		Bold red on pink		Fixed

Installation

VS Code

Clone into your VS Code extensions directory:

# Linux / macOS git clone https://github.com/glenzac/morninghue-theme ~/.vscode/extensions/morninghue # Windows git clone https://github.com/glenzac/morninghue-theme %USERPROFILE%\.vscode\extensions\morninghue

Then restart VS Code, open the Command Palette (Ctrl+Shift+P), type Preferences: Color Theme, and select MorningHue.

Vim / Neovim

mkdir -p ~/.vim/colors cp colors/morninghue.vim ~/.vim/colors/

Add to ~/.vimrc:

set background=light colorscheme morninghue

xterm (.Xresources)

cp morninghue.Xresources ~/.Xresources xrdb -merge ~/.Xresources

The ANSI white palette slots are remapped to dark values (color7 = #444444, color15 = #1c1c1c) so TUI tools like GitHub Copilot CLI render text visibly on the light background.

tmux

Add to ~/.tmux.conf:

source-file /path/to/morninghue.tmux.conf

dircolors (fixes broken symlinks)

Add to your shell rc file:

# bash / zsh [ -f /path/to/morninghue.dircolors ] && eval $(dircolors /path/to/morninghue.dircolors) # tcsh / csh if ( -f /path/to/morninghue.dircolors ) eval `dircolors -c /path/to/morninghue.dircolors`

Color Palette

Background & Foreground

AAA Tier — CR ≥ 7:1

AA Tier — CR ≥ 4.5:1

Code Examples

SystemVerilog

Python

C

Makefile

TCL

Bash / Shell

JSON

Markdown

UI Elements

Vim Statusline

tmux Status Bar

Diagnostics & Selection

Diff View

Broken Symlinks (ls --color)

Accessibility & Contrast Ratios

Why Accessibility Matters for Code

Comparison with PaperColor

Installation

VS Code

Vim / Neovim

xterm (.Xresources)

tmux

dircolors (fixes broken symlinks)