2nd/10_Wiki/Topic_CSS/CSS_RGB.md

id, title, category, status, verification_status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, created_at, updated_at, review_reason, merge_history, tags, raw_sources, applied_in, github_commit

id	title	category	status	verification_status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	created_at	updated_at	review_reason	merge_history	tags	raw_sources	applied_in	github_commit
css-rgb-colors	CSS RGB Colors	Frontend	draft	conceptual		RGB rgb() RGBA rgba() RGB color model CSS RGB values		B	0.89	2026-06-23	2026-06-23			css web frontend w3schools color rgb rgba	https://www.w3schools.com/css/css_colors_rgb.asp

CSS RGB Colors

🎯 한 줄 통찰 (One-line insight)

An RGB color value is defined with rgb(red, green, blue), where each light source ranges from 0 to 255, and rgba() adds an alpha channel (0.0–1.0) to control opacity. [S1]

🧠 핵심 개념 (Core concepts)

• RGB = Red, Green, Blue — colors are formed by combining these three light sources. [S1]
• Syntax — rgb(red, green, blue). [S1]
• Range — each parameter (red, green, blue) defines the intensity of the color from 0 to 255. [S1]
• How it mixes — rgb(255, 0, 0) is displayed as red, because red is set to its highest value (255) and the others are set to 0. [S1]
• Black and white — black is rgb(0, 0, 0); white is rgb(255, 255, 255). [S1]
• RGBA — RGBA extends RGB with an alpha channel for opacity: rgba(red, green, blue, alpha), where alpha ranges from 0.0 (fully transparent) to 1.0 (not transparent). [S1]

🧩 추출된 패턴 (Extracted patterns)

• Equal channels = gray — setting red, green, and blue to the same value produces a shade of gray. [S1]
• Max one channel — pushing a single channel to 255 while keeping the others at 0 produces a pure primary color (e.g. red, blue). [S1]
• Opacity via alpha — append an alpha value with rgba() to make the same color progressively more transparent. [S1]

📖 세부 내용 (Details)

RGB Value RGB colors represent Red, Green, and Blue light sources. The syntax is rgb(red, green, blue), where each parameter (red, green, and blue) defines the intensity of the color from 0 to 255. rgb(255, 0, 0) is displayed as red, because red is set to its highest value (255) and the others are set to 0. [S1]

Examples of RGB color values shown on the page: [S1]

rgb(255, 0, 0)    /* red */
rgb(0, 0, 255)    /* blue */
rgb(60, 179, 113) /* medium sea green */
rgb(238, 130, 238)/* violet */
rgb(255, 165, 0)  /* orange */
rgb(106, 90, 205) /* slate blue */

Black is rgb(0, 0, 0) and white is rgb(255, 255, 255). [S1]

Shades of Gray Shades of gray are often defined using equal values for all three light sources: [S1]

rgb(60, 60, 60)
rgb(90, 90, 90)
rgb(120, 120, 120)
rgb(180, 180, 180)
rgb(210, 210, 210)
rgb(240, 240, 240)

RGBA Value RGBA color values are an extension of RGB color values with an alpha channel, which specifies the opacity for a color. An RGBA color value is specified with rgba(red, green, blue, alpha). The alpha parameter is a number between 0.0 (fully transparent) and 1.0 (not transparent at all). [S1]

The page demonstrates the same color at increasing opacity: [S1]

rgba(255, 99, 71, 0)    /* fully transparent */
rgba(255, 99, 71, 0.2)
rgba(255, 99, 71, 0.4)
rgba(255, 99, 71, 0.6)
rgba(255, 99, 71, 0.8)
rgba(255, 99, 71, 1.0)  /* not transparent */

🛠️ 적용 사례 (Applied in summary)

The color values above are the page's own demonstration examples. No external project/commit applications found in the source.

💻 코드 패턴 (Code patterns)

RGB function (language: CSS):

selector {
  color: rgb(red, green, blue); /* each 0–255 */
}

RGBA function with opacity:

selector {
  color: rgba(red, green, blue, alpha); /* alpha 0.0–1.0 */
}

⚖️ 비교 및 선택 기준 (Comparison & decision criteria)

• RGB vs RGBA — use rgb() for an opaque color defined by red/green/blue intensities; use rgba() when the color also needs an opacity (alpha) value from 0.0 (fully transparent) to 1.0 (not transparent). [S1]

⚖️ 모순 및 업데이트 (Contradictions & updates)

No contradictions found in the source.

✅ 검증 상태 및 신뢰도

• 상태: draft
• 검증 단계: conceptual (실제 적용 사례 발견 시 applied/validated로 승격 가능)
• 출처 신뢰도: B (W3Schools — widely used educational reference, not a primary standards body)
• 신뢰 점수: 0.89
• 중복 검사 결과: 신규 생성 (New discovery)

🔗 지식 그래프 (Knowledge Graph)

• 상위/루트: CSS Tutorial
• 관련 개념: CSS HEX, CSS HSL, CSS Colors, CSS Background Color
• 참조 맥락: Referenced whenever a color must be defined numerically by light intensity, or whenever an opacity channel is needed via RGBA.

📚 출처 (Sources)

• [S1] W3Schools — CSS RGB Colors — https://www.w3schools.com/css/css_colors_rgb.asp

📝 변경 이력 (Change history)

• 2026-06-23: Initial draft synthesized from the W3Schools "CSS RGB Colors" page (Astra wiki-curation, P-Reinforce v3.1 format).