Dashboard line chart color

Can anyone help and check the below flow for modified function node. Am I doing it right ?

[{"id":"85de7d2a.d10f5","type":"ui_slider","z":"bc794abe.7829c8","name":"","label":"slider","tooltip":"","group":"a4448716.200ac8","order":2,"width":0,"height":0,"passthru":true,"outs":"all","topic":"","topicType":"str","min":"0","max":"100","step":"0.1","x":270,"y":2300,"wires":[["d58bdaf1.d93048"]]},{"id":"d58bdaf1.d93048","type":"function","z":"bc794abe.7829c8","name":"","func":"var last = context.get('last') || 'under'\nvar undermessage = {topic:'under',payload:null}\nvar overmessage = {topic:'over',payload:null}\nvar unsent = null\n\nif(msg.payload > 50){\n    if(last == 'under'){\n        undermessage.payload = 50\n        overmessage.payload = 50\n        unsent = msg\n    }\n    else{\n        overmessage.payload = msg.payload\n    }\n    last = 'over'\n}\nelse{\n    if(last == 'over'){\n        overmessage.payload = 0\n        undermessage.payload = 0\n        unsent = msg\n    }\n    else{\n        undermessage.payload = msg.payload\n    }\n    last = 'under'\n}\ncontext.set('last',last)\n\nreturn [[overmessage,undermessage],unsent]","outputs":2,"noerr":0,"initialize":"","finalize":"","libs":[],"x":440,"y":2300,"wires":[["277cf5b5.1c633a"],["3679a19c.ac113e"]]},{"id":"277cf5b5.1c633a","type":"ui_chart","z":"bc794abe.7829c8","name":"","group":"a4448716.200ac8","order":2,"width":0,"height":0,"label":"chart","chartType":"line","legend":"false","xformat":"HH:mm:ss","interpolate":"linear","nodata":"","dot":false,"ymin":"0","ymax":"100","removeOlder":1,"removeOlderPoints":"","removeOlderUnit":"60","cutout":0,"useOneColor":false,"useUTC":false,"colors":["#1f77b4","#ff0000","#ff7f0e","#2ca02c","#98df8a","#d62728","#ff9896","#9467bd","#c5b0d5"],"outputs":1,"useDifferentColor":false,"x":610,"y":2300,"wires":[[]]},{"id":"125535f9.c93eca","type":"inject","z":"bc794abe.7829c8","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[]","payloadType":"json","x":490,"y":2180,"wires":[["277cf5b5.1c633a"]]},{"id":"3679a19c.ac113e","type":"delay","z":"bc794abe.7829c8","name":"","pauseType":"delay","timeout":"20","timeoutUnits":"milliseconds","rate":"1","nbRateUnits":"1","rateUnits":"second","randomFirst":"1","randomLast":"5","randomUnits":"seconds","drop":false,"x":470,"y":2420,"wires":[["d58bdaf1.d93048"]]},{"id":"c0275527.f46528","type":"function","z":"bc794abe.7829c8","name":"modified","func":"var last = context.get('last') || 'under'\nvar undermessage = {topic:'under',payload:null}\nvar overmessage = {topic:'over',payload:null}\nvar midmessage = {topic:'mid',payload:null}\nvar unsent = null\n\nif(msg.payload >= 80 && msg.payload < 100)\n{\n    if(last == 'under'){\n        undermessage.payload = 0\n        overmessage.payload = 0\n        midmessage.payload = 0\n        unsent = msg\n    }\n    else{\n        overmessage.payload = msg.payload\n    }\n    last = 'over'\n}\n\nelse if (msg.payload >= 50 && msg.payload < 79)\n{\n    if(last == 'over'){\n        overmessage.payload = 0\n        undermessage.payload = 0\n        midmessage.payload = 0\n        unsent = msg\n    }\n    else{\n        midmessage.payload = msg.payload\n    }\n    last = 'mid'\n}\n\n\nelse (msg.payload >= 0 && msg.payload < 49)\n{\n    if(last == 'mid'){\n        overmessage.payload = 0\n        undermessage.payload = 0\n        midmessage.payload = 0\n        unsent = msg\n    }\n    else{\n        undermessage.payload = msg.payload\n    }\n    last = 'under'\n}\ncontext.set('last',last)\n\nreturn [[overmessage,undermessage,midmessage],unsent]","outputs":2,"noerr":0,"initialize":"","finalize":"","libs":[],"x":440,"y":2260,"wires":[[],[]]},{"id":"a4448716.200ac8","type":"ui_group","name":"LEVEL","tab":"6e01408.cda5dc","order":1,"disp":true,"width":"8","collapse":false},{"id":"6e01408.cda5dc","type":"ui_tab","name":"Home","icon":"track_changes","order":1,"disabled":false,"hidden":false}]

image