The approach to fixing this really lies in understanding the error message first of all and then diagnosing what's wrong.
The message is basically telling you that your query is incorrect and it can't figure out what you're asking.
At first glance you seem to provide all the necessary information "scheme", "mode" but you don't show anywhere what values you're passing...
So does "getColor" and "getSchemeMode" contain gobbledegook or valid values?
One approach would be to to construct your URL on a sepate line and then console.log the result so you can see what's being passed to the api OR even just logging the contents of those two variables and see what's there...
console.log(getColor);
console.log(getSchemeMode);
As a side-note, those are horrible names for variables... "getAnything" basically implies a function of some kind and not a variable so I'd avoid doing that.