Fix #30, rename nice colors, add "nice-" prefix

salt_observer/assets/less/variables.less

-@navy: #001f3f;
-@blue: #0074D9;
-@aqua: #7FDBFF;
-@teal: #39CCCC;
-@olive: #3D9970;
-@green: #2ECC40;
-@lime: #01FF70;
-@yellow: #FFDC00;
-@orange: #FF851B;
-@red: #FF4136;
-@maroon: #85144b;
-@fuchsia: #F012BE;
-@purple: #B10DC9;
-@black: #111111;
-@gray: #AAAAAA;
-@silver: #DDDDDD;
+@nice-navy: #001f3f;
+@nice-blue: #0074D9;
+@nice-aqua: #7FDBFF;
+@nice-teal: #39CCCC;
+@nice-olive: #3D9970;
+@nice-green: #2ECC40;
+@nice-lime: #01FF70;
+@nice-yellow: #FFDC00;
+@nice-orange: #FF851B;
+@nice-red: #FF4136;
+@nice-maroon: #85144b;
+@nice-fuchsia: #F012BE;
+@nice-purple: #B10DC9;
+@nice-black: #111111;
+@nice-gray: #AAAAAA;
+@nice-silver: #DDDDDD;