As far as I know one application can have only one icon in macOS.
Fixed by commit 3849480fd490bc7bf705a20b908b2201cbd22013 https://sourceforge.net/p/tuxpaint/tuxpaint/ci/3849480fd490bc7bf705a20b908b2201cbd22013/
macOS done: https://sourceforge.net/p/tuxpaint/tuxpaint/ci/98198591b54d8cba294588186fe62ce12bcdfab1/
Added Mark K. Kim to the list of developers.
Updated Mark K. Kim's contact information in various pages.
Korean contact page character set corrected (UTF-8 to EUC-KR), english fonts download page <h4> tag alignment consistency corrected by removing <p> tags.
Korean language support added. Several Korean pages (about, download, contacts) added.
Submitted: https://sourceforge.net/p/tuxpaint/tuxpaint/ci/7aa000b68a93f2d1a00a0fea33f29c409381d201/