now we have dark mode, use different colors for lines on graphs

templates/index.html

@@ -259,6 +259,10 @@
             // Highcharts configuration
             Highcharts.chart('container', {
                 chart: { type: 'line' },
+                colors: [
+                    'orange', // Custom color 1
+                    'cyan', // Custom color 2
+                ],
                 title: { text: 'Savings Over Time' },
                 xAxis: {
                     type: 'datetime',