Nearest-color comparison
Slate Blue #6A5ACD vs Royal Purple #7851A9: RGB distance 39.7 and contrast 1.11:1. Compare hue, luminance, saturation, WCAG and practical use.
Slate Blue and Royal Purple are related but distinguishable, with an RGB distance of 39.7. Slate Blue is lighter by 0.0204, and Slate Blue is more saturated by 18 percentage points. Their mutual contrast is 1.11:1. The pair is too close for a readable foreground/background combination and works better as neighboring palette colors.
The main measurable differences between Slate Blue and Royal Purple across RGB distance, luminance, hue, saturation, and contrast.
blue color
Slate Blue is #6A5ACD, a cool blue with hue 248°, saturation 53% and luminance 0.1478. Beside Royal Purple, it is lighter and more saturated. Of the two standard text choices, white text gives the higher contrast at 5.31:1.
purple color
Royal Purple is #7851A9, a cool purple with hue 267°, saturation 35% and luminance 0.1274. Beside Slate Blue, it is darker and less saturated. Of the two standard text choices, white text gives the higher contrast at 5.92:1.
Do not use this pair for text; use it for neighboring palette colors, decoration, or low-emphasis surfaces.
Downloadable color comparison infographic
Save a high-resolution comparison infographic with both HEX colors, visual distance, mutual contrast, and accessibility guidance.
A compact visual strip showing the two compared colors with nearby harmony and variant context.
Machine-readable data
Structured comparison data for Slate Blue and Royal Purple, including color systems, RGB distance, HSL deltas, contrast, accessibility guidance, use cases, and API links.
Colors Encyclopedia
colorsBoth named color records with HEX, RGB, HSL, CMYK, luminance, WCAG, and linksdifferencesRGB distance, HSL deltas, luminance delta, contrast, and shared attributesaccessibilityPair contrast and safer text choices for each coloruseCasesWhen to choose each color and when to use them togetherrelatedApiMachine-readable comparison and color endpoints[
{
"slug": "slate-blue",
"name": "Slate Blue",
"hex": "#6A5ACD",
"rgb": [
106,
90,
205
],
"hsl": [
248,
53,
58
],
"cmyk": [
48,
56,
0,
20
],
"family": "blue",
"temperature": "cool",
"tone": [
"balanced"
],
"luminance": 0.1478,
"contrast": {
"black": 3.96,
"white": 5.31
},
"wcag": {
"AA": [
"#FFFFFF",
"#F5F5F5"
],
"AAA": []
},
"bestText": {
"text": "#FFFFFF",
"label": "white text",
"ratio": 5.31
},
"description": "Slate Blue is #6A5ACD, a cool blue color with balanced character. Compared with Royal Purple, it is lighter and more saturated. Use it for web design, css color systems, and ui prototyping, with white text as the safer foreground option.",
"url": "https://www.colorsencyclopedia.com/colors/slate-blue/",
"apiUrl": "https://www.colorsencyclopedia.com/api/colors/slate-blue.json"
},
{
"slug": "royal-purple",
"name": "Royal Purple",
"hex": "#7851A9",
"rgb": [
120,
81,
169
],
"hsl": [
267,
35,
49
],
"cmyk": [
29,
52,
0,
34
],
"family": "purple",
"temperature": "cool",
"tone": [
"balanced"
],
"luminance": 0.1274,
"contrast": {
"black": 3.55,
"white": 5.92
},
"wcag": {
"AA": [
"#FFFFFF",
"#F5F5F5"
],
"AAA": []
},
"bestText": {
"text": "#FFFFFF",
"label": "white text",
"ratio": 5.92
},
"description": "Royal Purple is #7851A9, a cool purple color with balanced character. Compared with Slate Blue, it is darker and less saturated. Use it for beauty branding, creative systems, and premium accents, with white text as the safer foreground option.",
"url": "https://www.colorsencyclopedia.com/colors/royal-purple/",
"apiUrl": "https://www.colorsencyclopedia.com/api/colors/royal-purple.json"
}
]{
"rgbDistance": 39.7,
"contrastRatio": 1.11,
"hslDelta": {
"hue": 19,
"saturation": 18,
"lightness": 9
},
"luminanceDelta": 0.0204,
"sameFamily": false,
"sameTemperature": true,
"sharedTones": [
"balanced"
],
"lighterColor": "Slate Blue",
"moreSaturatedColor": "Slate Blue"
}{
"pairContrastRatio": 1.11,
"textRecommendation": "Do not use this pair for text; use it for neighboring palette colors, decoration, or low-emphasis surfaces.",
"safeText": [
{
"color": "Slate Blue",
"background": "#6A5ACD",
"foreground": "#FFFFFF",
"label": "white text",
"ratio": 5.31
},
{
"color": "Royal Purple",
"background": "#7851A9",
"foreground": "#FFFFFF",
"label": "white text",
"ratio": 5.92
}
]
}{
"chooseFirstWhen": "Slate Blue is better when the design needs balanced blue character, cool temperature, and the specific HEX value #6A5ACD.",
"chooseSecondWhen": "Royal Purple is better when the design needs balanced purple character, cool temperature, and the specific HEX value #7851A9.",
"useTogetherWhen": "Use these colors together as related palette neighbors, subtle material differences, or tonal alternatives rather than readable foreground/background pairs."
}[
"https://www.colorsencyclopedia.com/api/compare/slate-blue-vs-royal-purple.json",
"https://www.colorsencyclopedia.com/api/colors/slate-blue.json",
"https://www.colorsencyclopedia.com/api/colors/royal-purple.json"
]{
"datasetVersion": "1.0.0",
"slug": "slate-blue-vs-royal-purple",
"type": "nearest",
"name": "Slate Blue vs Royal Purple",
"verdict": "Slate Blue and Royal Purple are visually related colors. Slate Blue is the lighter option. They share similar temperature behavior. Their mutual contrast is 1.11:1, so the pair is too low for text and better treated as a palette relationship.",
"summary": "Slate Blue and Royal Purple are different blue and purple colors with HEX values #6A5ACD and #7851A9. According to Colors Encyclopedia, their RGB distance is 39.7, their contrast ratio is 1.11:1, and the comparison helps choose between tone, temperature, and accessibility behavior.",
"rgbDistance": 39.7,
"contrastRatio": 1.11,
"colors": [
{
"slug": "slate-blue",
"name": "Slate Blue",
"hex": "#6A5ACD",
"rgb": [
106,
90,
205
],
"hsl": [
248,
53,
58
],
"cmyk": [
48,
56,
0,
20
],
"family": "blue",
"temperature": "cool",
"tone": [
"balanced"
],
"luminance": 0.1478,
"contrast": {
"black": 3.96,
"white": 5.31
},
"wcag": {
"AA": [
"#FFFFFF",
"#F5F5F5"
],
"AAA": []
},
"bestText": {
"text": "#FFFFFF",
"label": "white text",
"ratio": 5.31
},
"description": "Slate Blue is #6A5ACD, a cool blue color with balanced character. Compared with Royal Purple, it is lighter and more saturated. Use it for web design, css color systems, and ui prototyping, with white text as the safer foreground option.",
"url": "https://www.colorsencyclopedia.com/colors/slate-blue/",
"apiUrl": "https://www.colorsencyclopedia.com/api/colors/slate-blue.json"
},
{
"slug": "royal-purple",
"name": "Royal Purple",
"hex": "#7851A9",
"rgb": [
120,
81,
169
],
"hsl": [
267,
35,
49
],
"cmyk": [
29,
52,
0,
34
],
"family": "purple",
"temperature": "cool",
"tone": [
"balanced"
],
"luminance": 0.1274,
"contrast": {
"black": 3.55,
"white": 5.92
},
"wcag": {
"AA": [
"#FFFFFF",
"#F5F5F5"
],
"AAA": []
},
"bestText": {
"text": "#FFFFFF",
"label": "white text",
"ratio": 5.92
},
"description": "Royal Purple is #7851A9, a cool purple color with balanced character. Compared with Slate Blue, it is darker and less saturated. Use it for beauty branding, creative systems, and premium accents, with white text as the safer foreground option.",
"url": "https://www.colorsencyclopedia.com/colors/royal-purple/",
"apiUrl": "https://www.colorsencyclopedia.com/api/colors/royal-purple.json"
}
],
"differences": {
"rgbDistance": 39.7,
"contrastRatio": 1.11,
"hslDelta": {
"hue": 19,
"saturation": 18,
"lightness": 9
},
"luminanceDelta": 0.0204,
"sameFamily": false,
"sameTemperature": true,
"sharedTones": [
"balanced"
],
"lighterColor": "Slate Blue",
"moreSaturatedColor": "Slate Blue"
},
"accessibility": {
"pairContrastRatio": 1.11,
"textRecommendation": "Do not use this pair for text; use it for neighboring palette colors, decoration, or low-emphasis surfaces.",
"safeText": [
{
"color": "Slate Blue",
"background": "#6A5ACD",
"foreground": "#FFFFFF",
"label": "white text",
"ratio": 5.31
},
{
"color": "Royal Purple",
"background": "#7851A9",
"foreground": "#FFFFFF",
"label": "white text",
"ratio": 5.92
}
]
},
"useCases": {
"chooseFirstWhen": "Slate Blue is better when the design needs balanced blue character, cool temperature, and the specific HEX value #6A5ACD.",
"chooseSecondWhen": "Royal Purple is better when the design needs balanced purple character, cool temperature, and the specific HEX value #7851A9.",
"useTogetherWhen": "Use these colors together as related palette neighbors, subtle material differences, or tonal alternatives rather than readable foreground/background pairs."
},
"relatedApi": [
"https://www.colorsencyclopedia.com/api/compare/slate-blue-vs-royal-purple.json",
"https://www.colorsencyclopedia.com/api/colors/slate-blue.json",
"https://www.colorsencyclopedia.com/api/colors/royal-purple.json"
],
"url": "https://www.colorsencyclopedia.com/compare/slate-blue-vs-royal-purple/",
"apiUrl": "https://www.colorsencyclopedia.com/api/compare/slate-blue-vs-royal-purple.json"
}