Setting color when using datum

[jankuca]

Hello,

I am trying to figure out a combination of datum and some custom color configuration but I cannot seem to get to one.

Is it possible to override the automatically selected colors when using encoding.color.datum?

Here is an example vega spec of one of my tries: setting mark.color

Another approach I took is specifying the encoding.color.scale.scheme but that gives a warning about the unexpected use of datum in such case.

Is there any other way?

Any help much appreciated, thanks!

[jwoLondon]

It's not quite clear to me what you are wanting to achieve here. In your first example you correctly set the colour of all bar marks to "red", but then you also add a further colour encoding with datum:"label" which is not necessary and is preventing the bars from being assigned a red colour. Simply removing your colour encoding line ( "color": {"datum": "label"}) will solve that particular problem.

In your second example, are you wanting the value of w to influence the colour of the mark that represents it? If so, you'd replace datum:"label" with field:"w". This is the standard way in which you indicate which data you want to influence the encoding.

It is possible to be more precise in colour allocation than just using a colour scheme, but whether you go down that route I think depends on what exactly you want to achieve.