taiga-front/app/styles/components/markdown-help.scss

a.help-markdown,
a.help-button {
    @extend %small;
    color: $gray-light;
    &:hover {
        span {
            @include transition(color .2s linear);
            color: $grayer;
        }
        .icon {
            @include transition(color .2s linear);
            color: $fresh-taiga;
        }
    }
    .icon {
        color: $gray-light;
        margin-right: .2rem;
    }
}