Binaural Beats meets Sound-Color-Synesthesia Binaural beats, the perception of which arises in the brain for specific physical stimuli. ... The effect on the brainwaves depends on the difference in frequencies of each tone: for example, if 300 Hz was played in one ear and 310 in the other, then the binaural beat would have a frequency of 10 Hz. [Wiki]


Does someone with the form of  Sound-Color-Synesthesia, see the color connected with the 10Hz tone, when hearing 300/310 Hz tones?

Does it work otherway round as well? Are there even examples known?

What light does this shed, on how the brain works (maybe restricted to the Synesthesia people)?

Edit is there anyone around here who can test that? Experience reports are welcome.
Unfortunately, it appears there is currently no research investigating how synaesthetes experience the binaural beats effect. If any such research does exist, it does not appear to be available (in English) via Google Scholar, Web of Science or Scopus. 

Furthermore, there is little research on binaural beats generally. I covered some of the scarce research that does exist on binaural beats in my answer to the question, "Is there scientific evidence on the benefits of binaural beats?", which may be of some interest to you. However, the findings are generally inconclusive and do not allow us to theorize on how a synaesthete might experience the binaural beats effect. On the evidence, therefore, it is currently equally conceivable that synaesthetes do or do not experience binaural beats differently from healthy participants at all.