I'm trying to use the what-if worksheet to get a rough idea of the proportional tax liability for each of my wife and I who file MFJ. I open the worksheet and check the MFJ vs MFS box but for many categories the number in the taxpayer and spouse columns is just an equal split of the MFJ total. For example, interest, dividends, and capital gains are all split 50-50 even though the 1099s are specifically attributed to either taxpayer or spouse. The income that is appropriately attributed is wages, taxable IRA distributions, taxable pensions, and taxable social security. Why aren't all income categories correctly attributed?
Also, is there some meaning to blue numbers on a tan background vs. black numbers on a white background? Sometimes the coloration is the same for an entire row and sometimes there is a different coloration for taxpayer vs spouse?