Resizing shelf icons to fit its space - icons

Question

I have created two shelf buttons and icons but in the image attachment I have put up, you can see that the yellow icon seems to be working correctly but as for the blue icon, it is sticking to the top-left hand corner of its 'space'
The initial sizing I have created for the yellow icon is 32 x 32 pixels while the blue one is 20 x 20 pixels
Both shelf attributes are pretty much the same but I am unable to get the blue icon to either match in size or have it be in the center.
Thus are there any other ways in which I can resize it, have it in a reasonable sizing like the yellow one without creating another new image to 32 x 32 pixels?
// -------- 32 x 32 pixels --------
shelfButton
-enableCommandRepeat 0
-enable 1
-width 34
-height 34
-manage 1
-visible 1
-label "Yellow Icon"
-image "icon_yellow.png"
-style "iconOnly"
;
// -------- 20 x 20 pixels --------
shelfButton
-enableCommandRepeat 0
-enable 1
-width 34
-height 34
-manage 1
-visible 1
-label "Blue Icon"
-image1 "icon_blue.png"
-style "iconOnly"
;

Answer 1

You need to remove -label flag and add -scaleIcon and iconAndTextHorizontal style.
Tested on the 2016 version.
// -------- 20 x 20 pixels --------
shelfButton
-enableCommandRepeat 0
-enable 1
-width 34
-height 34
-manage 1
-visible 1
-image1 "icon_blue.png"
-scaleIcon // scale
-style "iconAndTextHorizontal"// need for scale
;