添加tabBar，在app.json中代码如下

"tabBar": {

        "color": "#9FB9BA",

        "selectedColor": "#00AAA8",

        "backgroundColor": "#1F2346",

        "borderStyle": "white",

        "position": "bottom",

        "list": [{

            "pagePath": "pages/exhibition/exhibition",

            "text": "1",

            "iconPath": "images/exhibition-white.png",

            "selectedIconPath": "images/exhibition-active.jpg"

        }, {

            "pagePath": "pages/museum/museum",

            "text": "2",

            "iconPath": "images/museum-white.png",

            "selectedIconPath": "images/museum-active.png"

        }, {

            "pagePath": "pages/spreadtrum/spreadtrum",

            "text": "3",

            "iconPath": "images/spreadtrum-white.png",

            "selectedIconPath": "images/spreadtrum-active.png"

        }, {

            "pagePath": "pages/mine/mine",

            "text": "4",

            "iconPath": "images/mine-white.png",

            "selectedIconPath": "images/mine-active.png"

        }]

    }

图片统一81X81的，但是显示很有问题，请问能够外部修改tabBar的样式吗