The designers claim copyright over the Autistic Pride Day logo. The designers are Australian. To the best of my knowledge after reading about Australian copyright law, and after putting this up for discussion on the Village Pump/Copyright, it appears this image would not actually be copyrightable in Australia.

The copyright / terms of use that the designers have on their website is as follows:

Just Gold Digital Agency (ABN 20 630 605 926) owns or licenses from third parties all of the trademarks, copyright and other intellectual property that exists related to autisticprideday.org. You may only download and use the AUTISTIC PRIDE DAY logo and material from autisticprideday.org for the non-commercial purpose of promoting AUTISTIC PRIDE DAY.

You must not edit, alter, warp or display the AUTISTIC PRIDE DAY logo in any way which is contrary to the purpose of AUTISTIC PRIDE DAY as expressed on autisticprideday.org. For the avoidance of doubt, this includes any purpose that is:

• Opposed to the inclusion of neurodiverse people and identities.
• Disrespectful, hateful, or negative towards any person or group of people.
• Negative towards AUTISTIC PRIDE DAY, Just Gold Digital Agency or any partners or entities represented on autisticprideday.org.

Content posted by you Any content that you create or post online using the AUTISTIC PRIDE DAY logo or materials (eg photos, videos and comments) is your responsibility, and you must make sure that you have the necessary rights to post that content (eg by obtaining permission of copyright owners if necessary or by obtaining permission to use personal information of third parties). By posting any content, you also give Just Gold Digital Agency a non-exclusive, transferable, royalty-free worldwide right to use and reproduce that content.

This image of simple geometry is ineligible for copyright and therefore in the public domain, because it consists entirely of information that is common property and contains no original authorship.