Change Merger Styling

i m using code mirror merge view for file difference , every this is working fine except for style (highlighting difference), is there a way to change the styling except for changing classes in merge,js

{
                chunk: "CodeMirror-merge-l-chunk",
                start: "CodeMirror-merge-l-chunk-start",
                end: "CodeMirror-merge-l-chunk-end",
                insert: "CodeMirror-merge-l-inserted",
                del: "CodeMirror-merge-l-deleted",
                connect: "CodeMirror-merge-l-connect"
            }
            : {
                chunk: "CodeMirror-merge-r-chunk",
                start: "CodeMirror-merge-r-chunk-start",
                end: "CodeMirror-merge-r-chunk-end",
                insert: "CodeMirror-merge-r-inserted",
                del: "CodeMirror-merge-r-deleted",
                connect: "CodeMirror-merge-r-connect"
            };

i m unable to change classes through configuration my current confing is

var target = document.getElementById("view");

    target.innerHTML = "";
    dv = CodeMirror.MergeView(target, {
        addModeClass:true,
        value: value,
        origLeft: null,
        origRight: null,
        orig: orig2,
        lineNumbers: true,
        mode: "text/html",
        highlightDifferences: highlight,
        connect: null,
        collapseIdentical: collapse,
        allowEditingOriginals: true,
        theme: 'mdn-like',
        /* chunk: "testing",
        classes:{chunk: "testing",
            start: "testing",
            end: "testing",
            insert: "testing",
            del: "testing",
            connect: "testing"} */
        /* chunkClassLocation: {
            left:{


            chunk: "testing",
            start: "testing",
            end: "testing",
            insert: "testing",
            del: "testing",
            connect: "testing"
            },
            right:{


            chunk: "testing",
            start: "testing",
            end: "testing",
            insert: "testing",
            del: "testing",
            connect: "testing"
            }
        }, */


    });

also containing my testing samples