Here is a CSR script:
SP.SOD.executeFunc("clienttemplates.js", "SPClientTemplates", function() {
function getBaseHtml(ctx) {
return SPClientTemplates["_defaultTemplates"].Fields.default.all.all[ctx.CurrentFieldSchema.FieldType][ctx.BaseViewID](ctx);
}
function init() {
SPClientTemplates.TemplateManager.RegisterTemplateOverrides({
Templates: {
Fields: {
"PercentageOfTargetAchieved": {
View: function(ctx) {
var percentage = ctx.CurrentItem["Inspections"] / 100;
switch (true) {
case (percentage >= 1):
return "<span style='color: green'>" + ctx.CurrentItem["PercentageOfTargetAchieved"];
break;
case (percentage >= .5 && percentage < 1):
return "<span style='color: orange'>" + ctx.CurrentItem["PercentageOfTargetAchieved"];
break;
case (percentage < .5):
return "<span style='color: red'>" + ctx.CurrentItem["PercentageOfTargetAchieved"];
break;
default:
return ctx.CurrentItem["PercentageOfTargetAchieved"];
}
},
}
},
},
ListTemplateType: 100
});
}
RegisterModuleInit(SPClientTemplates.Utility.ReplaceUrlTokens("~siteCollection/Style Library/AchievementColorCoding.js"), init);
init();
});
I don't know the name of your columns so you might have to adjust the corresponding parts of the code. Also, the conditions you have mentioned don't cover the percentage range of >50% && <75%. I think that's a mistake so the script has the ranges
Red: <50%
Orange: >=50% && <100%
Green: >=100%
UPDATE
After reading your comments, here is some updated code.
Assuming that you have the columns JL, JL% (internal name: JL_x0025_) and Target:
SP.SOD.executeFunc("clienttemplates.js", "SPClientTemplates", function() {
function getBaseHtml(ctx) {
return SPClientTemplates["_defaultTemplates"].Fields.default.all.all[ctx.CurrentFieldSchema.FieldType][ctx.BaseViewID](ctx);
}
function init() {
SPClientTemplates.TemplateManager.RegisterTemplateOverrides({
Templates: {
Fields: {
"JL_x0025_": {
View: function(ctx) {
var percentage = ctx.CurrentItem["JL"] / ctx.CurrentItem["Target"]
switch (true) {
case (percentage >= 1):
return "<span style='color: green'>" + ctx.CurrentItem["JL_x0025_"];
break;
case (percentage >= .5 && percentage < 1):
return "<span style='color: orange'>" + ctx.CurrentItem["JL_x0025_"];
break;
case (percentage < .5):
return "<span style='color: red'>" + ctx.CurrentItem["JL_x0025_"];
break;
default:
return ctx.CurrentItem["JL_x0025_"];
}
},
}
},
},
ListTemplateType: 100
});
}
RegisterModuleInit(SPClientTemplates.Utility.ReplaceUrlTokens("~siteCollectio/Style Library/AchievementColorCoding.js"), init);
init();
});
Screenshot:

You'll have to adjust the path in the RegisterModuleInit-function if you want it to work with activated Minimal Download Strategy.