Sometimes you need a color scheme quick, and ColorBrewer is typically the de facto, but it has some limitations. You can’t just choose any color you want as a starting point, and there is a set number of color schemes. Colorgorical by Connor Gramazio on the other hand lets you set parameters and color ranges, and it spits out a scheme with perceptual differences.
The interface is a bit rough, but usable enough to get some nice colors.