Worth a try - it could be Q. Robur which is very common (it's actually called 'common oak') and although used sometimes for barrels is not preferred flavour-wise.
Q petraea is the French white oak.
Look around for some Q. alba - American White Oak - You'll know it immediately if you can get them to cut a piece - smells strongly of bourbon when freshly cut (it's so good!!) - very fine grain.
You've not toasted them enough from the photos - as a guide see the attached photos of American Oak pieces -
This was taken from pieces used in an on-going oaking test - T1 is the 'oaky' range in the previous chart i posted, T2 is Sweet, T3 Vanillin - Unfortunately I think the samples may be wet from the look of paler ones - however the T3 sample equates to a 'Medium' toast and is the most common - needs to be a chocolate colour - note the grooves cut in the top of each so I know which toast level they are (mainly for the lighter ones and to differentiate when charred (charring only penetrates abput a mil or 2)
The bottles where photgraphed on 22/2/15 - You can see the varied colour achieved from each toast level in 3 weeks. The dark sample has an old charred stave piece - You can see the effect of the different toast levels and charring. The smell and taste from each toast level is markedly different and changes with time. I was surprised by the depth of colour from the old stave piece - It was a bigger piece and heavily charred though (was only added as an afterthought comparison - not part of the 'proper' trial).
The test continues...(I'm keeping notes) - On 22/2/15, I halved the samples of the T1/T2/T3 batches, halved the oak pieces and charred half of them. As they are today is shown in the last pic - The light is a bit lower than in the 2015 pic but you can still see the changes. Note that also, the T2 Char sample was heat teated for 5 days in July 2015 - You can see the darkening effect - It has a deeper colour than the T3 Char sample.
You can also see that most of the colour is extracted quite early in the process. So colouring up is only the very beginning of the aging process, and does not indicate maturity
I've also attached a photo of the SD medium toast dominoes as a colour guide - these would equate to T3
Happy New Year and happy toasting/soaking/charring !!