// Band combinations
var natural = ['B4', 'B3', 'B2'];
var swir = ['B6', 'B5', 'B3'];
var urban = ['B7', 'B6', 'B4'];
var veg = ['B5', 'B4', 'B3'];

// Get a Landsat scene
var scene = ee.Image('LANDSAT/LC8_L1T_TOA/LC80450332015263LGN00');

// Convert the RGB bands to the HSV
var hsv = scene.select(urban).rgbToHsv();

// Add band 8 and convert back to RGB
var sharpened = ee.Image.cat([
  hsv.select('hue'), hsv.select('saturation'), scene.select('B8')
]).hsvToRgb();

// Do a very basic color correction
var imageRGB = sharpened.visualize({min: 0, max:0.18,
              gamma:[
                1.05, // red
                1.08, // green
                0.8]  // blue
});

// Display the image and zoom to it
Map.addLayer(imageRGB);
Map.centerObject(sharpened, 9);