Add colored QSlider for all themes

themes/console_style/console_style.qss

@@ -18,6 +18,13 @@ QPlainTextEdit {
 	selection-color: rgb(0, 0, 0);
 }
 
+QSlider::sub-page:horizontal {
+    background-color: #ff9900;
+}
+QSlider::sub-page:vertical {
+    background-color: #ff9900;
+}
+
 QComboBox {
     border: 0px solid transparent;
     border-radius: 2px;

themes/dark/dark.qss

@@ -109,6 +109,13 @@ QStackedWidget {
 	background: #232629;
 }
 
+QSlider::sub-page:horizontal {
+    background-color: #4545e5;
+}
+QSlider::sub-page:vertical {
+    background-color: #4545e5;
+}
+
 /*************************************
 Progressbar
 **************************************/

themes/elegant_dark/elegant_dark.qss

@@ -17,6 +17,13 @@ QSplitter::handle {
     background-color: transparent;
 }
 
+QSlider::sub-page:horizontal {
+    background-color: #00ff00;
+}
+QSlider::sub-page:vertical {
+    background-color: #00ff00;
+}
+
 QTreeView {
 	background-color: transparent;
     selection-background-color: transparent;

themes/material_design_dark/material_design_dark.qss

@@ -26,6 +26,13 @@ QSplitter::handle {
     background-color: transparent;
 }
 
+QSlider::sub-page:horizontal {
+    background-color: #88cc00;
+}
+QSlider::sub-page:vertical {
+    background-color: #88cc00;
+}
+
 /*************************************
 Main menu (Bar)
 **************************************/

themes/material_design_light/material_design_light.qss

@@ -26,6 +26,13 @@ QSplitter::handle {
     background-color: transparent;
 }
 
+QSlider::sub-page:horizontal {
+    background-color: #6ECE12;
+}
+QSlider::sub-page:vertical {
+    background-color: #6ECE12;
+}
+
 /*************************************
 Main menu (Bar)
 **************************************/