They are soft, cozy and quiet. Crocheted of Red Heart® Bamboo Wool (55% viscose from bamboo, 45% wool). The sole and the lace are made of leather. Left on a parquet floor they look as a part of interior. It can be custom-made in other color combination and sizes.
Here you can see color swatches of this yarn: http://www.coatsandclark.com/Products/KnittingCrochet/Yarns/Medium/Red+Heart+Bamboo+Wool.htm
Available in dark blue (see 3845 twilight), rust (see 3340 rust), bright green (see 3650 dill) and deep red (see 3920 cayenne).