I'm trying to dissolve, subdue (What's the correct term?) that glaring, brazen, straight clear cut boundary between the blue and green. I want the blue and green to gradient and meld smoothly (What's the correct term?) into each other. I'm using GIMP, as COVID unemployed me.
Isn't it faster and productiver to use the Blur/Sharpen Tool?
If you recommend the Blur/Sharpen Tool, must I click it along the whole length of the boundary between the two colors? How many times must I click it at the boundary?