What Is the Difference Between Asagi-iro and Light Blue? Let’s Compare Their Blue and Green Tones

Asagi-iro and mizuiro (light blue) both look blue, but they are not the same color. Asagi-iro is commonly used for a stronger blue-green, while mizuiro is a pale, airy blue. Exact color swatches vary between references, so this article uses asagi-iro ■#00A3AF and mizuiro ■#BCE2E8 as examples. We will compare their blue and green tones, brightness, and saturation, then look at how to use them in web design.

Asagi-iro is vivid blue-green; mizuiro is a lighter shade

Hue describes the direction of a color, such as blue or green. Saturation describes how vivid it is, while lightness describes how light or dark it appears. The hues of these two particular swatches are quite close. Rather than labeling asagi-iro simply green and mizuiro simply blue, it is more accurate to compare their lightness and saturation too.

• Asagi-iro ■#00A3AF: Its RGB values are red 0, green 163, and blue 175. RGB is a way of representing red, green, and blue light with values from 0 to 255. With substantial green and blue components and no red, this swatch appears as a vivid blue-green.
• Mizuiro ■#BCE2E8: Its RGB values are red 188, green 226, and blue 232. Green and blue are also relatively high, but its much higher red component brings the channels closer together and makes the color appear pale and closer to white.

In both examples, the blue value is slightly higher than the green value. So the difference cannot be explained simply by asking which has more blue. Mizuiro can also have a greenish cast, while the strongest difference between these two swatches is their brightness and vividness. HEX is a six-digit hexadecimal code for representing an RGB color on the web.

Using both colors on a waterfront event website

Example 1: Make asagi-iro the main event color. Use asagi-iro ■#00A3AF across the upper part of an announcement banner, with the event name and date in deep blue-green ■#0E2B34. The contrast ratio between the text and background is approximately 4.85:1. A contrast ratio measures the difference in relative luminance between two colors; this combination exceeds the 4.5:1 level required for ordinary text under the relevant accessibility guideline.

In a lower panel, place practical information such as what to bring or how to get there on mizuiro ■#BCE2E8. Dark blue-green ■#0E2B34 text gives approximately 10.74:1 against that panel. In this layout, the stronger asagi-iro sets the identity of the event and the pale mizuiro organizes detailed information.

Example 2: Make light blue the main background. Give the page a white ■#FFFFFF background and use broad mizuiro ■#BCE2E8 sections for venue details and registration instructions. Dark blue-green ■#0E2B34 body text contrasts at about 10.74:1. Add asagi-iro ■#00A3AF sparingly as a short heading strip or a labeled color sample to create variation within the pale page.

For a registration button, choose a darker variation of asagi-iro, deep teal ■#005663, with white ■#FFFFFF text. The text-to-button contrast ratio is approximately 8.36:1, while the button contrasts with the mizuiro ■#BCE2E8 background at approximately 6.05:1. You do not need to use the original asagi-iro swatch for every word or button; adjusting its depth to match the element’s job is more useful.

Compare blue and green tones separately from readability

To compare the colors, place equal-sized swatches on the same white ■#FFFFFF background. Look at hue, but also check the difference in saturation and lightness. Screen settings and neighboring colors can change how a color appears, so use the actual HEX values that will be applied to the final design instead of relying on color names alone.

Asagi-iro ■#00A3AF and white ■#FFFFFF have a contrast ratio of approximately 3.06:1. White text on asagi-iro therefore does not meet the 4.5:1 threshold for ordinary-size text. Mizuiro ■#BCE2E8 and white ■#FFFFFF have a ratio of approximately 1.38:1, so a pale-blue card may have an indistinct boundary on a white page. Where separation matters, add an outline or enough space.

WCAG 2.2, the Web Content Accessibility Guidelines, requires at least 4.5:1 contrast for normal-size text and 3:1 for large text at Level AA. Visual cues needed to identify interactive controls may also need 3:1 against adjacent colors. Asagi-iro ■#00A3AF and mizuiro ■#BCE2E8 contrast with each other at only about 2.21:1, so do not communicate an essential selected state through the difference between those two colors alone.

HueRoll accepts HEX codes rather than color names for direct entry. It can show contrast against white and black for the selected color, but it does not automatically compare any two arbitrary colors or assess AA compliance. Check the exact pairs in your design separately.