fn parse_modern_alpha(
context: &ParserContext<'_>,
arguments: &mut Parser<'_>,
allowed_channel_keywords: ChannelKeyword,
) -> Result<ColorComponent<NumberOrPercentageComponent>, ParseError>fn parse_modern_alpha(
context: &ParserContext<'_>,
arguments: &mut Parser<'_>,
allowed_channel_keywords: ChannelKeyword,
) -> Result<ColorComponent<NumberOrPercentageComponent>, ParseError>