Apparently, the most frequently used ligands contain unsaturated N-atoms of Schiff-bases, porphyrins, phthalocyanins, etc. (There are also examples for C=C double bonds, S-donors etc.) Due to variety of the ligands I am not sure that the colors can be generalized based on the oxidation state of Sn.  See some perhaps useful links: http://eprints.qut.edu.au/1000/1/Arnold_CCR_revised_text3.pdf ; http://www.iasj.net/iasj?func=fulltext&aId=42349 ; http://rasayanjournal.co.in/vol-3/issue-3/25.pdf ; http://link.springer.com/article/10.1163%2F1568567042420794#page-1 ; http://www.znaturforsch.com/ab/v58b/s58b1030.pdf ; https://en.wikipedia.org/wiki/Organotin_chemistry ;  http://www.hindawi.com/journals/bca/2010/854514/ ; http://www.ncbi.nlm.nih.gov/pubmed/9397578 ; http://pubs.rsc.org/en/content/articlelanding/2011/dt/c0dt01426e#!divAbstract

You can find a lot more continuing searching in browsers.

Thanks Dr. Imre Tóth. I checked few of these literature before.

Thanks Dr. Imre Tóth. I checked few of these literature before.

Alright. As you see there are plenty of examples for both Sn(II) and Sn(IV).