Am I Color Blind or What?

Question

Ok, I’m a beginner in gardening so please forgive if I’m being rude.

I’m reforming my garden and I choose to use Ageratum Houstonianum in it. Now, I’m having a problem with its colors. More specifically its nomenclature.

While searching for the plant I feel in love with a very rare blue tone, very similar to a blue hawaii. Like this:

However, this seems to be a very rare kind of such plant, because every time I search for Blue ageratum more than half of the my findings are this “blue”:

Now, this is not a blue, it’s a shade of purple leaning to pink called Lilac. This is no way blue, the sky is blue, the earth is blue, this is not blue.

I found many other variations of ageratum with blue in its name “ageratum hawaii blue”, ageratum blue mink, ageratum blue mist. But none of them are really blue (in the pictures at least) like the ones I found before, so my question is this:

Are the people who gave the common names to this plant color blind or the flower’s color change depending on the soil’s pH? If so, a minor pH would make it more bluish like it does with hydrangeas?

Answer 1

Color is often difficult to describe. When you "Google" Ageratum Houstonianum , the first 3 images are all a different color blue. If you know for fact that is what you have, ask for it by botanical name rather than common name. Yes, common names can be frustrating, that's why growers use botanical names instead. (Also, pictures can be frustrating when taken with different filters, lighting and other factors.) While not sure of pH affecting bloom color, using an acidic fertilizer won't hurt...just be sure not to use too much and reduce blooming.