If you want to change your lineart color on PaintTool SAI, the easiest way is by using Lock Opacity.
Remember to check the box Colorize, and Preview to see live edits.
Use Lock Opacity to change the color of pixels in a selected lineart layer.Always create your lineart on a separate layer than your sketch and color to make future edits painless.Method 2: Using the Hue and Saturation Filter.
