Yeah it’s the opacity tool but it leaves dark spots

Are you sure you're not using the spray tool? You find the opacity thing when you tap the color wheel and look under the colors, you should find some blue line saying opacity 100%

But the opacity tool leaves ugly dark spots if I hold it down for 4s

1- Choose the color you like 2- go to the opacity option at the bottom of the preset colors 3-make the opacity 1% or 2% 4- start coloring over the same spot at least 5-6 or 7 times while slowly making the area you color smaller, so go from a big circle to smaller and smaller etc 🟠⭕️⏺️ I could make a tutorial!

Pls tell me