选中的区域有些颜色变了，这是为什么？下面是brush配置
brush: {
default: ['rect', 'polygon', 'keep', 'clear'],
brushStyle: {
borderWidth: 2,
borderColor: 'rgba(0,0,0,0.5)',
},
seriesIndex: 'all',
throttleType: 'debounce',
throttleDelay: 'debounce',
geoIndex: 'all'
},