Here's a little more on Tamboro I just googled--only here the sun is described as being bluish. My first source, Tales of the Earth did not mention this bluish color:

Recognition of the climatic changes associated with volcanic eruptions can be traced back to 1783, when Benjamin Franklin observed the "dry fog" in Europe following the Laki Fissure eruption in Iceland. In fact, historical records are quite useful to re-write the history of the effects of past eruptions on past climates. Records that describe prolonged darkness, cold summers and colder winters, failed crops, and famine, all indicate post-eruption conditions. After the 1883 Krakatoa eruption, observations of atmospheric optical phenomenon were made, including blurring of celestial objects, an odd bluish color of the sun, and extreme sunrises and sunsets (Rampino, Self and Stothers, 1988).

Examples of climate change due to past volcanic eruptions

Perhaps one of the best known climatic alterations due to a volcanic eruption is the year 1816; the "year without a summer" following the 1815 Tambora eruption on Sumbawa Island in Indonesia. Tambora is one of the largest known eruptions in the past 10,000 years (Rampino, Self, and Stothers, 1988). It produced ash fallout over a 4x105 km2 area and caused darkness for about 2 days as far away as 600 km from the volcano. Studies including tree ring observations, indicate that the 1816 summer was approximately 1.5 °C cooler than the summer of 1815. The year following the eruption was one of hardship felt across the globe. The summer was cold and wet in western Europe, crops failed, people starved, disease spread and social unrest grew (Rampino, Self, and Stothers, 1988).


http://www.geo.umn.edu/courses/1001/climate_natural.html