Please take a look at Rendering Charts from JSON API using AJAX for step to step instruction on rendering chart from JSON data. Also, kindly check this gallery example for chart from JSON data in PHP. Could you please provide the sample JSON data returned from myphpService.php so that we can look into the data and help you out?
Can you please check your Browser Console for any errors? Also, can you please create a sample project and share your code, so that we can look into it and help you out.
Can you please open up the Browser Console and check if there is any error. Also, can you please create a jsfiddle reproducing the issue so that we can look into the code and help you out better.
Please download this sample which uses ASP.NET and ORACLE for rendering CanvasJS Chart.
A readme file has been included for your convenience with all the instructions to set up the project and get the charts running.
Glad you figured it out. Also, you can set the legend marker color using the legendMarkerColor property. Please take a look at this documentation page for more information.