So you're probably seeing a lot of dress/parade uniforms. The Austro-Hungarian army did traditionally wear white, a color the Austrians adopted in the 18th century at least in part as a cost saving measure since it didn't require dye (that's from Richard Bassett's "For God and Kaiser").

Later on the Austro-Hungarian army switched to a dark blue uniform, and then in 1908 moved to the "pike grey" which will be the light blue you see. Now this doesn't mean you don't see the dark blue. Due to supply issues for new gear six(!) years later, the Austro-Hungarian army was forced to issue old uniforms (and also use stores of the previous rifle which had been out of service for nearly 20 years by then). From Alexander Watson's new work "Fortress", on the crucial siege of Przemsyl:

"The regiments, all of older men, wore a mix of uniforms. Some had been issued modern pike gray ; others had made good shortages by distributing clothing in more conspicuous obsolete dark blue."

Now in late 1915 the Austrians moved to a more German grey due to the fact that light blue actually was suboptimal on a battlefield from the" don't get shot "metric, but again due to supply issues you continue to see previous uniform patterns through the conflict, and some color variations (some a bit greener).