Clip monitor: use marker category's color as background

src/monitor/view/MonitorRuler.qml

@@ -553,7 +553,6 @@ Rectangle {
             }
             Rectangle {
                 visible: !rulerMouseArea.pressed && (guideArea.containsMouse || (rulerMouseArea.containsMouse && Math.abs(rulerMouseArea.mouseX - markerBase.x) < 4))
-                opacity: 0.7
                 property int guidePos: markerBase.x - mlabel.contentWidth / 2
                 x: guidePos < 0 ? 0 : (guidePos > (parent.width - mlabel.contentWidth) ? parent.width - mlabel.contentWidth : guidePos)
                 radius: 2

src/monitor/view/kdenliveclipmonitor.qml

@@ -492,7 +492,7 @@ Item {
                 width: fontMetrics.boundingRect(displayText).width + 10
                 horizontalAlignment: displayText == text ? TextInput.AlignHCenter : TextInput.AlignLeft
                 background: Rectangle {
-                        color: "#990000ff"
+                    color: controller.markerColor
                 }
                 color: "#ffffff"
                 padding: 0