I might be able to assist Mr Verbist… 
Have you seen these ??
What you need is a Function node to isolate the Button Events, then query the state of your Hue Lights and act accordingly.
You can have a seperate Flow or DSL rule to change the state of the feedback LEDs dependant on the state of the HUE Thing.
Give me a shout if you need more information… (you’re the one that got me on Slack in the first place)
A pair of DSL rules might look like this
rule "Velbus button to Hue lamp"
when
Channel "velbus:vmbgp1:xxxxxxx:ch1" triggered PRESSED
then
if (Hue_Lamp_Switch.state == ON)
{ Hue_Lamp_Switch.sendCommand(OFF)
}
else
{ Hue_Lamp_Switch.sendCommand(ON)
}
end
rule "Hue Lamp to Velbus feedback"
when
Item Hue_Lamp_Switch changed
then
if (triggeringItem.state == ON)
{
VelbusGP1ButtonFeedback.sendCommand("SET_LED")
}
else
{
VelbusGP1ButtonFeedback.sendCommand("CLEAR_LED")
}
end