I am often asked why the model has different colors on it. Waxes come in different colors. Some colors are random and some are indicative of the wax working properties or readability. The hard waxes come in blue, purple, and green with blue being the most flexible and green being the most brittle. Because of the cross form becoming so thin I prefer to use the most flexible of the hard waxes which offers less chance of it breaking and gives me a smoother line when scraping the wax shape.
Hard waxes are plasticized so cannot be hot tooled without creating strings similar to a hot glue gun effect. The red wax I use is very soft and easy for me to sculpt soft forms on top of the hard wax cross form. It is applied by melting small pieces on a hot tool and trailed along the model building it up in desired places, then shaping with hot or cold tools.
The little balls of wax are applied by letting the hot ball of wax run down the pointed needle tool touching the hard wax form at just the right time. I may have to scrape and reapply over and over until I get it right as it is not an exacting application process.
Another reason I like to use waxes of differing colors is for readability. It is hard to see the tiny details I'm adding if there is not a color contrast between the waxes. The color variations of the pomegranate seeds occurred more randomly due to the wax I happened to pick up for the bead.