カラーコンバーター

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HEX、RGB、HSL間で色を変換

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カラーコンバーター の使い方

  1. 1サポートされている任意のフォーマットでカラー値を入力
  2. 2すべてのフォーマットに即座に変換される
  3. 3ライブカラープレビューを確認

カラーコンバーター について

カラーコンバーターは HEX、RGB、RGBA、HSL、HSLA フォーマット間でカラー値を変換する包括的なツールです。ライブカラープレビューを表示します。

カラーコンバーターの主な機能

  • Convert between HEX, RGB, RGBA, HSL, and HSLA instantly
  • Enter any format and all others update simultaneously
  • Visual color preview swatch updates in real time
  • Browser color picker for interactive color selection
  • Supports both 3-digit (#RGB) and 6-digit (#RRGGBB) HEX formats
  • Handles alpha/transparency channel in RGBA and HSLA
  • One-click copy for each color format
  • Works entirely in-browser — no server requests

対応フォーマット

入力フォーマット

HEX (#RRGGBB, #RGB)RGB (rgb(r, g, b))RGBA (rgba(r, g, b, a))HSL (hsl(h, s%, l%))HSLA (hsla(h, s%, l%, a))

出力フォーマット

HEXRGBRGBAHSLHSLA

cornflowerblue などの名前付き CSS カラーは入力としてサポートされていません。

使用例

Convert a Figma HEX color to HSL for CSS

Translate a design tool HEX value to HSL for use in CSS custom properties.

入力

#3B82F6

出力

RGB: rgb(59, 130, 246) | HSL: hsl(217, 91%, 60%) | HSLA: hsla(217, 91%, 60%, 1)

Add transparency to an RGB color

Get the RGBA equivalent of a solid color with 50% opacity for a semi-transparent overlay.

入力

rgb(0, 0, 0) with alpha 0.5

出力

RGBA: rgba(0, 0, 0, 0.5) | HEX with alpha: #00000080

主な使用ケース

  • Translating HEX colors from design tools (Figma, Sketch) into CSS RGB or HSL values
  • Converting solid colors to RGBA for semi-transparent overlays and backgrounds
  • Using HSL values for programmatic lightening and darkening in CSS custom properties
  • Bridging color formats between front-end code and back-end APIs
  • Verifying that different format representations of a color are equivalent
  • Quickly checking the RGB values of a HEX color in a design spec

トラブルシューティング

HEX value produces a different color than expected

解決策

HEX values are case-insensitive but must be exactly 3 or 6 hexadecimal digits after the #. Ensure you have not missed a character — #FF0 (3-digit) and #FF0000 (6-digit) are both valid red.

HSL hue value is out of range

解決策

HSL hue is a value from 0 to 360 degrees. Saturation and lightness are percentages (0–100%). Enter values within these ranges to get a valid color.

Alpha value in RGBA/HSLA is not working

解決策

Alpha is a value from 0 (fully transparent) to 1 (fully opaque). Values like 0.5 represent 50% opacity. Do not enter a percentage — use a decimal between 0 and 1.

よくある質問

What color formats are supported?

HEX (#RRGGBB and #RGB), RGB (rgb(r, g, b)), RGBA (rgba(r, g, b, a)), HSL (hsl(h, s%, l%)), and HSLA (hsla(h, s%, l%, a)). Enter any format and all others are calculated instantly.

What is the difference between RGB and HSL?

RGB defines colors as intensities of red, green, and blue light. HSL defines colors by hue (0–360°), saturation (0–100%), and lightness (0–100%). HSL is more intuitive for adjusting color properties — changing lightness darkens or lightens a color without affecting its hue.

When should I use RGBA instead of HEX?

Use RGBA when you need transparency (alpha channel). HEX does not natively support transparency in all browsers (HEX with alpha is #RRGGBBAA). RGBA is the most universally compatible format for transparent colors in CSS.

What does the alpha value in RGBA represent?

Alpha (the fourth value in RGBA) represents opacity: 0 is fully transparent, 1 is fully opaque. Values like 0.5 give 50% transparency, allowing the background to show through.

Can I convert CSS named colors like "cornflowerblue"?

Named CSS colors are not currently supported as input. You can find the HEX value of any named color from a CSS reference and enter the HEX value to convert to other formats.

Is there a difference between HEX shorthand (#RGB) and full HEX (#RRGGBB)?

#RGB is shorthand for #RRGGBB where each digit is doubled. #F80 equals #FF8800. Both represent the same color; shorthand is only valid when both digits of each pair are identical.

Is my data sent to a server?

No. All conversions are performed locally in your browser using JavaScript math. No data is transmitted anywhere.

Can I use this to find the HSL lightness of a color?

Yes. Enter the HEX or RGB value and the HSL output shows the lightness percentage. You can then adjust the lightness in your CSS to create lighter or darker variants of the same hue.