False color image (red: 0.2–0.7 keV, green: 0.7–1.1 keV, blue: 1.1–10 keV) of the X-ray emitting bubble S308. The star WR6 shines in the center of the bubble. The red line indicates the source extraction region, while the blue line indicates the background one. The smoothing algorithm is based on the work of Ebeling et al. (2006) and is applied as described in Sect. 3.1. The image scaling has been considerably stretched to highlight the faint soft X-ray diffuse emission of the nebula.