A decorative painting kit including multiple-color paint applicators and a method of decoratively painting a surface though in situ surface blending of two or more paints of different colors by using a multiple-color paint applicator which is stroked over the same surface a sufficient number of time to at least partially blend the different paint colors. The methods generally comprise ionizing a dihydroxyvitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. A subset of these safe network configuration sets may then be selected for implementation using hardening costs as a criterion. The speakers thus convert electrical energy outputted from the audio system into sound energy, and radiate the sound energy into air inside the mattress, thus acoustically vibrating the mattress.