Kangxi Radical Red

It is a dictionary index form, not a color message. ⾚ is Kangxi radical 155, the red heading in a traditional index for Han characters. A radical-and-stroke lookup groups entries under a chosen component, then narrows them by the strokes left over. 赤 is the ordinary character used in text.

In oracle-bone inscriptions (writing carved on bones used for divination), the ordinary character 赤 already meant red. Later bronze inscriptions use the word for red animal hides and ritual clothing. That history belongs to 赤, not the separately encoded radical ⾚.

Why use a radical-and-stroke lookup?

It gives readers an entry point by component and stroke count. A reader finds a character under one selected radical, then narrows the candidates by the strokes that remain.

Chinese dictionary tradition also records senses such as bare, empty, and sincere for 赤. Japanese dictionaries list red and bare meanings, plus a sense connected with children. The Shuowen Jiezi, an early Chinese character dictionary, groups 赧, 赭, and 赫 in its 赤 section.

When do I need the exact radical form?

Use ⾚ when the radical code point is what the entry requires. Unicode treats ⾚ as compatible with 赤 but assigns them separate code points. Some fonts draw them nearly alike, so their appearance alone cannot confirm which character a text contains.