First off, wow, you're being an ass.
Second off, instead of bashing me as Some Guy On The Internets, put on your critical thinking cap, read the source text, and educate yourself.
I'll even make it easy for you and copy out the relevant section from page 26 (bolding mine):
Article VII Section 1 SECTION 1 TAXATION. The power of taxation
shall never be suspended, surrendered or contracted away.
All taxes shall be uniform upon the same class of property
within the territorial limits of the authority levying the tax
and shall be levied and collected for public purposes only.
The word "property" as used herein shall mean and include
everything, whether tangible or intangible, subject to ownership.
So for Washington state law, as relates to the state Constitution, "property" would include income.
If your beef is with the word "levy" instead, again, read the source text. You'll find that the word "levy" is used in the more general sense of "to impose or collect by legal authority; the imposition or collection of an assessment". See the Merriam-Webster entry if you'd like.
Search the text of the Constitution itself, and you'll find collocations like the one in the blockquote above, where "taxes" are "levied". Notably, this is not the same thing as a federal IRS levy, which is what you seem to be thinking about. It's important to recognize that different branches and levels of government sometimes use the same terms in different ways.
Cheers,