In iOS 9, U+2714 HEAVY CHECK MARK
is included in Apple's set of emoji characters. Just like the other emojis, it's drawn as a full-color bitmap instead of a single-color vector glyph, so you can't change its color with CSS. (In fact, there's no guarantee that the check mark will even be black. Other platforms draw it in a variety of different colors!)
To get iOS to draw the check mark as regular text that you can recolor, you need to use a U+FE0E VARIATION SELECTOR-15
character. If you put that variation selector character right after a ?, iOS will use the regular text version (?︎) instead of the emoji version (?). OS X doesn't have an emoji variant, so these look the same, but on iOS the variants look slightly different:
In HTML, you can add the character by putting a ︎
directly following your check marks.
div {
color: red;
}
<div>
? without variation selector<br>
?︎ with variation selector
</div>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…