Do you mean sulfuric acid or sulfur dioxide in water?

Sulfonation or sulfination seems likely. Aryl sulfinates are not particularly stable and tend to disproportionate which could explain your transient colour change.

Resorcinol is made commercially by disulfonation-fusion of benzene (see the reference: http://link.springer.com/chapter/10.1007/3-540-28090-1_2#page-1  ).

Technical-grade resorcinol (the one usually used in labs.)may have some sulfur impurities which played a role in a side reaction route that led to an unstable product (i.e. other than resorcinol sulfite).

I found this:  Resorcinol disulfonic acid (HO)2C6H2(HSO3)2, is a hygroscopic mass obtained by the action of sulfuric acid on resorcin. It is easily soluble in water (as it absorbs moisture readily) and decomposes when heated to 100 °C.  Perhaps this is what you formed?

The reaction with resorcinol (rather than resorcin) may have yielded a slightly different compound than what I just posted above...  but am not exactly sure what that would be.  But, the fact that you observed the crystals going from bright yellow to colorless may be indicative of the resulting adduct's propensity to gather moisture from the atmosphere.  Interesting compound!

Are you sure about having spilled H2SO3????????

The ''acid'' was SO2 dissolved in water.

So, the "acid" was most likely H2SO4 (instead of H2SO3) then according to:

2 SO2 + 2 H2O + O2 → 2 H2SO4

A related aside on this:

"Sulfur dioxide, SO2, is a colorless gas or liquid with a strong, choking odor.  It is produced from the burning of fossil fuels (coal and oil) and the smelting of mineral ores (aluminum, copper, zinc, lead and iron) that contain sulfur. 

"Sulfur dioxide dissolves easily in water to form sulfuric acid..."  

http://www.dhs.wisconsin.gov/eh/chemfs/fs/SulfurDioxide.htm