Format of animatable value for color only properties

Hello,
I was facing the introduction of discrete and continuous animations in my ttml engine.

I saw animate tag requires style-namespace properties to adhere to the <animation-value-list> and then the <animation-value> properties.

So, for example, for what concerns tts:color, we can have something like this (took from specs):

<animate xml:id="a1" keyTimes="0;0.2;1" tts:color="red;green;blue"/>

In the definitions of animatable styles, I saw some that are not exactly clear and for which I found no tests nor examples.

These following properties, report the "color only" marker on the "Animatable" row:

 - tts:border
 - tts:textEmphasis
 - tts:textOutline
 - tts:textShadow

As their color is animatable, I was wondering about the following details:

1) the "color only" applies only on continuous animation, so either on <set> element or <animate> with calcMode = "linear" | "paced" | "spline". Is this correct?
2) What is the syntax that one should write when, for example, tts:border is animated? Reporting all the attributes for each keyTime? For example:

tts:border="2px solid red; 2px solid green; 2px solid blue"

or

tts:border="2px solid red; green; blue"

In my ignorance, both could be fine (even the second sounds weird, if I give a look at <animation-value-list>)


Furthermore, assuming the first case is the right one or at least one of the two supported, let's take the following example:


tts:border="2px solid red; 5px solid green; 10px dashed blue"


I see three possible outcomes with this expression, when a continuous calcMode is used:

- this is an error: only color should be supported
- this is valid but only color is kept in consideration: when the keyTimes progresses, we'll have both "2px solid green" and "2px solid blue"
- this is valid but only color is animated continuously. The rest of the properties are animated discreetly.

Which of the above is correct?

Thank you very much for your support,
Alexander