I noticed that and they did it for Nitrates also.
Notice the new chart on the right. The 10-20 are little darker...
Also in the new chart the 20,40 and 80 all look the same. Banging my head...
"When creating an aqua scape, strive for the beauty of imperfection, as its art and there is no wrong or right, it's left open for interpretation" James Findley