Hi Frederick and welcome.
First, you didn’t indicate which Launchpad type you have. The buttons and colors are different depending on the type
LaunchPad S and Launchpad MINI
The button assignment and color mapping are shown in the respective manuals on the Novation web site. The Lauchpad MINI doesn’t have a manual but has the same command and colors as the Launchpad-S.
I assume you have a Lauchpad Mk2 or Pro since you said you wanted a blue button and the original Launchpad, Launchpad-S, and Launchpad MINI cannot create blue.
I’ve included an example project file for you.
There are two presets. One handles button lighting LED feedback back to the Launchpad. The other handles the keystrokes going to Premier Pro (or whatever application you have in focus).
The way I’ve set up the LED’s is toggle. On first keypress the light goes on and press same button again and light goes off. I have set two buttons. The first with light color blue and the second with color red.
I have two global variables indicating the state of each light. 1 = light on 2=light off.
I have rules to toggle the values on each key press.
For the Adobe output, I’ve set it to only send keystroke if pressing turns the light on. I’m not sure that is what you are looking for but should give you the idea.
Please open the project file and try it. You can look at the rules to see how I’ve handled toggle functions:
Example for blue light
//Toggle ga 1=on 2=off
// Turn on blue light
if ga==1 then pp=79
// Turn off light
if ga==0 then pp=0
Output rules to only send keystroke if light is on
if ga==0 then exit rules, skip Outgoing Action
Also you can use Capture MIDI for incoming rules if you don’t know what a given button outputs. You can then simply click the preferred input to capture it in the translator.
Let me know if this helps set you on the right path and if you need further assistance.