[Solved]-Change Y Axis vertical line color in Highcharts-Highcharts

You can use style in yAxis.labels for the label colors, and gridLineColor for the line colors:

yAxis: {
    labels: {
        style: {
            color: 'red'
        }
    },
    gridLineColor: 'red'
}

http://jsfiddle.net/fehjnp5a/1/