orange breast

Since we will be discussing the orange breast zebrafinch (PO) in this article, it is certainly interesting to dwell a bit on the history of this mutation first.
The orange breast mutation (PO) is believed to have originated in Belgium. I consciously write "supposed" because the first orange breast (PO) was actually found at a bird merchant. In Dutch literature in particular, long before the discovery of the first orange breast (PO) in Belgium, zebra finches were described there with characteristics that we can now attribute to orange breast (PO) wearers.
What we are certain of anyway is that the honor of the discovery of the orange breast (PO) goes to a certain Mr. De C. who in 1978 noticed a rather special gray male in a store. This male had an orange breast bar when normally it should have been black. Mr. DE C. bought this copy, but at the breeding nothing came out of what he had hoped for. At the end of 1978, Paul CH., President of the BZC at that time, acquired this male. There were good and bad surprises with this subject, because unfortunately this male did not live very long. Fortunately Paul CH. had been able to get some young people before. Orange breast (PO) is inherited autosomal recessively compared to the wild form. The orange factor must therefore be doubly present to become visible. He therefore crossed young people between them and quickly took out the first orange breasts (PO).

Already the first orange breast breeder (PO) made the mistake of not combining and developing the orange breast (PO) with classic colors (gray, brown, pale back, masked) but he rushed directly on the combination of the orange breast with black breast (PN) and other mutations. From that moment on, every orange breast breeder’s dream was born to produce an all-orange zebra finch.
Due to having burned the breeding stage in the classic colors, the following question remained :

Are there any specific characteristics that we see in our classic orange breasts, are they just annoying derivatives of the presence of the black breast mutation (PN) or are these specific effects of the orange breast mutation ?

What do I mean by that? Often the orange chest gray or orange chest brown reveal not well defined cheeks. Likewise, there is often an orange hem on the fenders. Also, the chest frequently flows upwards and the belly shows patterns. All these observed characteristics are quite disturbing.