var collection = ee.ImageCollection('COPERNICUS/S5P/OFFL/L3_CH4')
.select('CH4_column_volume_mixing_ratio_dry_air')

.filterDate('20190101', '20190215');

var band_viz = {
min: 1750,
max: 1900,
palette: ['black', 'blue', 'purple', 'cyan', 'green', 'yellow', 'red']
};
//Map.addLayer(collection.mean(), band_viz, 'S5P CH4');
//Map.addLayer(geometry, {color :'silver'}, 'PAK');
Map.addLayer(collection.mean(), band_viz, 'S5P CH4');
Map.setCenter(0.0, 0.0, 2);