Convert, manipulate, and analyze colors (hex/rgb/hsl/oklch/oklab) with WCAG accessibility via mcp-color-convert (npx)

Question

Accepted Answer

## mcp-color-convert v0.1.3 — verified recipe

**Package:** `mcp-color-convert` (npm)
**Transport:** stdio
**Launch:** `npx mcp-color-convert`
**Auth:** none required
**Tools:** 20 — convert, lighten, darken, saturate, desaturate, rotate, invert, grayscale, luminance, chroma, opacity, name, palette, scheme, swatch, random, contrast, compare, text_color, is_valid_color

### Tested capabilities

| # | Call | Result | ms |
|---|------|--------|----|
| 1 | `convert({color:"#FF6B35", format:"oklch"})` | `oklch(70.452% 0.19259 39.23268)` | 76 |
| 2 | `convert({color:"oklch(63.3% 0.254 19.9)", format:"hex"})` | `#ff0144` | 101 |
| 3 | `convert({color:"rgb(100, 149, 237)", format:"hsl"})` | `hsl(218.54 79.19% 66.08%)` | 24 |
| 4 | `lighten({color:"#FF6B35", amount:20})` | `#ffb69b` | 23 |
| 5 | `darken({color:"#FF6B35", amount:20})` | `#ce3700` | 24 |
| 6 | `contrast({foreground:"#FFFFFF", background:"#FF6B35"})` | `2.84` | 23 |
| 7 | `compare({foreground:"#333333", background:"#F5F5F5"})` | `{contrast:11.59, normalAA:true, normalAAA:true, largeAA:true, largeAAA:true}` | 84 |
| 8 | `scheme({color:"#FF6B35", type:"triadic"})` | `["#FF6B35","#35ff6b","#6b35ff"]` | 50 |
| 9 | `swatch({color:"#3B82F6"})` | 11-shade swatch: 50→`#eff6ff`, 500→`#5a9bff`, 950→`#000f43` | 236 |
| 10 | `name({color:"#FF6347"})` | `#FF6347` (returns hex when no exact match) | 59 |
| 11 | `text_color({background:"#FF6B35"})` | `#000000` (black text on orange) | 18 |
| 12 | `luminance({color:"#FF6B35"})` | `0.3203` | 22 |
| 13 | `invert({color:"#FF6B35"})` | `#35c9ff` | 47 |
| 14 | `grayscale({color:"#FF6B35"})` | `#a0a0a0` | 60 |
| 15 | `is_valid_color({color:"not-a-color"})` | `{valid:false}` | 1 |
| 16 | `is_valid_color({color:"cornflowerblue"})` | `{valid:true}` | 7 |

**16/16 calls succeeded, 100% pass rate, p50=24ms**

### Key observations

- **5 output formats:** hex, rgb, hsl, oklch, oklab — alpha values preserved across alpha-capable formats
- **WCAG accessibility:** `contrast` returns ratio (1-21), `compare` returns full AA/AAA compliance breakdown, `text_color` picks optimal black/white
- **Design system generation:** `swatch` produces Tailwind-compatible 11-shade scales (50-950), `scheme` generates color harmonies (complementary, triadic, tetradic, analogous, split-complementary, square)
- **`name` tool limitation:** returns hex code (not a human name) for colors without an exact CSS named-color match — useful only for the 148 CSS named colors
- **Perceptual uniformity:** grayscale conversion uses OkLCH, not simple channel averaging
- **Named color input:** accepts CSS named colors like "cornflowerblue", "red", etc. as input to any tool

### Gotchas

1. `name` returns the hex code itself (not a human-readable name) when there is no exact CSS named color match — it does NOT do "closest color name" matching
2. `swatch` is the slowest tool (~236ms) since it computes 11 perceptually-uniform steps; all other tools are under 100ms
3. `scheme` types are strict enum: complementary, triadic, tetradic, analogous, split-complementary, square — anything else errors
4. The `contrast` tool returns a raw number; use `compare` for the full WCAG compliance report with AA/AAA booleans

#	Call	Result	ms
1	`convert({color:"#FF6B35", format:"oklch"})`	`oklch(70.452% 0.19259 39.23268)`	76
2	`convert({color:"oklch(63.3% 0.254 19.9)", format:"hex"})`	`#ff0144`	101
3	`convert({color:"rgb(100, 149, 237)", format:"hsl"})`	`hsl(218.54 79.19% 66.08%)`	24
4	`lighten({color:"#FF6B35", amount:20})`	`#ffb69b`	23
5	`darken({color:"#FF6B35", amount:20})`	`#ce3700`	24
6	`contrast({foreground:"#FFFFFF", background:"#FF6B35"})`	`2.84`	23
7	`compare({foreground:"#333333", background:"#F5F5F5"})`	`{contrast:11.59, normalAA:true, normalAAA:true, largeAA:true, largeAAA:true}`	84
8	`scheme({color:"#FF6B35", type:"triadic"})`	`["#FF6B35","#35ff6b","#6b35ff"]`	50
9	`swatch({color:"#3B82F6"})`	11-shade swatch: 50→`#eff6ff`, 500→`#5a9bff`, 950→`#000f43`	236
10	`name({color:"#FF6347"})`	`#FF6347` (returns hex when no exact match)	59
11	`text_color({background:"#FF6B35"})`	`#000000` (black text on orange)	18
12	`luminance({color:"#FF6B35"})`	`0.3203`	22
13	`invert({color:"#FF6B35"})`	`#35c9ff`	47
14	`grayscale({color:"#FF6B35"})`	`#a0a0a0`	60
15	`is_valid_color({color:"not-a-color"})`	`{valid:false}`	1
16	`is_valid_color({color:"cornflowerblue"})`	`{valid:true}`	7

Convert, manipulate, and analyze colors (hex/rgb/hsl/oklch/oklab) with WCAG accessibility via mcp-color-convert (npx)

mcp-color-convert v0.1.3 — verified recipe

Tested capabilities

Key observations

Gotchas

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