As I see you are a new member, I'd first like to welcome you to Tropical Fish Keeping forum.
Second, I'll mention our profiles, under the second heading from the left in the blue bar of the header of the page. Hornwort is one of the plants included.
As it mentions in the profile, the light intensity determines the colour. Temperature should not matter to this species, as your tank is within the indicated range.
When selecting plants for an aquarium, one thing to keep in mind is that some plants have specific requirements when it comes to light, from either very minimal to very intense. Sometimes it takes a bit of trial and error to find plants that are "compatible" in your situation which can include temperature, water hardness, as well as light. If the Hornwort is growing nicely and remaining lush green, consider yourself lucky; many try this plant and have it fall to pieces.
To the group of plants, yes, those are sword plants. Probably the species is Echinodorus grandiflorus grandiflorus. There are a few species that develop largish leaves on a very long stem, like Echinodorus cordifolius which is in our profiles [click shaded name] but you will see the leaf shape is different. E. g. grandiflorus has round base lobes unlike E. cordifolius which is chordate. But this is no guarantee, as the emersed and submersed leaf forms can change in many species. But your plants are definitely Echinodorus swords.