One kind: Remove axle pin (under hubcap) & slide out. Another : The axle has a flat-indentation that will not allow removal from the braces. You must remove the braces & turn them to align the slots. Yet another: more modern: A spring-steel clip that 'bites' the axle. Often has a plastic or tin cover. Replacements found on eBay. Post a picture... get an exact answer. The years of Radio Flyer is more than me !
Yes, the Epson default color scheme/formula/plan (whatever its called) needs a touch of blue in its BLACK. A different color scheme will often combine (different amounts) of colors. No two schemes are the same. I especially like the H-P printer setup asking "what color grey"... I didn't know grey was a color. What is it called - light black ? When you print something, check the defaults where you chose B&W, for the scheme Epson "VIVID" (I think thats the name) and change it to something else. My WorkForce is set to use "RGB-color" and prints with the blue-black. My H-P Laser is "sRGB" something different than regular RGB??? The H-P black is much finer resolution, but not as dark as Epson's blue-black. I also notice the Epson leafy green (blue+yellow), different than H-P grass-green (blue+yellow+black). Considering all of todays printer choices; I'm afraid plain-old-B&W is no longer vogue. I have an old LaserJetIII that blasts Black on white paper. Thats it.