To avoid a hectic workspace, we strongly recommend you only use white icons.
Find the logo you need and make sure it’s a transparent image. You can recognise a transparent image when you see the little white and grey blocks in de background. E.g. below:
Edit the image (e.g. in Photoshop) and make the logo white. Next resize the picture to 76 by 76 pixels.
If you are unable to this or you can’t be bothered, request your icon here!