The great thing about Japanese is that if you would like to translate your name by meaning, you have a number of kanji to choose from :) The way in which your name would be pronounced would be determined by the kanji and will probably be different than the reading of the kanji as it stands alone. So while Kuro = 黒; kawa= 川; Shiro = 白; Nami= 波; 並; or 浪 (there may be more, but these are what come to mind), you the pronunciation would change when you put them together. Also, when choosing which kanji to use, you can consider more than just the meaning. Factors like stroke number and popularity of the kanji in a name can be also used to chose which you'll lose. Some number of stroke orders are considered lucky. Also, some kanji are used by royalty more than "commoners."
On the other hand, the translator gives a phonetic translation. Most people who are not native Japanese or of Japanese heritage will translate their name into romaji based upon the phonetic translation of their native name. Although there are some famous artists and athletes who choose to adopt kanji names. It should be noted that this can sometimes be seen as trying to be Japanese when you're not.