1) Open World --- > Environment Settings ---- > Environment Editor and click on Advanced Sky, then click on “New” and save under a filename you remember, for example avatar 1

2) go to the Atmosphere Tab and change the settings as follow:
Blue Horizon:     R: 0.12,        G: 0.12,         B: 0.16,         I: 0.16
Haze Horizon:    0.09

Blue Density:     R: 0.32,        G: 0.59,         B: 1.00,         I: 1:00
Haze Density:   0.65

Density Multiplier:     0.18
Distance Multiplier:   2.0
Max Altitude:              188

3) go to the Lighting Tab and change the settings as follow:
Sun/Moon Color: R, G, B and I at       0.86
Sun/Moon Position:      0.000

Ambient:     R:0.67,        G:0.64,        B:0.63,        I:0.67 
              or   R: 0.70,        G: 0.67,       B: 0.66,      I: 0.70 (second setting is brighter)
East Angle: 0.16

Sun Glow: Focus: 0.10       Size 1.75
Scene Gamma:     1.08-1.15
Star Brightness:  0.00

4) go to the Clouds Tab and change the settings as follow:
Cloud Coverage:    0.13