For this kid you have some extended masking going on rather than just sable. Also this kid is too light to be liver. Liver is basically chocolate. Looks more isabella due to the lightness of the base. Being chocolate/isabella, the sable tips and masking would also be chocolate/isabella to avoid the dog being mistaken as a chim/somatic. otherwise good entry.
http://www.doggenetics.co.uk/ is a good reference site.
pheno wise you just need to change the base to isabella and add extending masking to your description. ^^